Co-reporter:Xianfu Wang;Bin Liu;Qiufan Wang;Weifeng Song;Xiaojuan Hou;Di Chen;Yi-bing Cheng
Advanced Materials 2013 Volume 25( Issue 10) pp:
Publication Date(Web):
DOI:10.1002/adma.201370061
Co-reporter:Xianfu Wang;Bin Liu;Qiufan Wang;Weifeng Song;Xiaojuan Hou;Di Chen;Yi-bing Cheng
Advanced Materials 2013 Volume 25( Issue 10) pp:1479-1486
Publication Date(Web):
DOI:10.1002/adma.201204063
Co-reporter:Gui Chen;Zhe Liu;Bo Liang;Gang Yu;Zhong Xie;Hongtao Huang;Bin Liu;Xianfu Wang;Di Chen;Ming-Qiang Zhu
Advanced Functional Materials 2013 Volume 23( Issue 21) pp:2681-2690
Publication Date(Web):
DOI:10.1002/adfm.201202739
Abstract
Zn3As2 is an important p-type semiconductor with the merit of high effective mobility. The synthesis of single-crystalline Zn3As2 nanowires (NWs) via a simple chemical vapor deposition method is reported. High-performance single Zn3As2 NW field-effect transistors (FETs) on rigid SiO2/Si substrates and visible-light photodetectors on rigid and flexible substrates are fabricated and studied. As-fabricated single-NW FETs exhibit typical p-type transistor characteristics with the features of high mobility (305.5 cm2 V−1 s−1) and a high Ion/Ioff ratio (105). Single-NW photodetectors on SiO2/Si substrate show good sensitivity to visible light. Using the contact printing process, large-scale ordered Zn3As2 NW arrays are successfully assembled on SiO2/Si substrate to prepare NW thin-film transistors and photodetectors. The NW-array photodetectors on rigid SiO2/Si substrate and flexible PET substrate exhibit enhanced optoelectronic performance compared with the single-NW devices. The results reveal that the p-type Zn3As2 NWs have important applications in future electronic and optoelectronic devices.
Co-reporter:Xianfu Wang;Weifeng Song;Bin Liu;Gui Chen;Di Chen;Chongwu Zhou
Advanced Functional Materials 2013 Volume 23( Issue 9) pp:1202-1209
Publication Date(Web):
DOI:10.1002/adfm.201201786
Abstract
Organic-inorganic hybrid photoelectric devices draw considerable attention because of their unique features by combining the relatively low ionization potential of the organic molecules and the high electron affinity of inorganic semiconductors. Hybrid organic-inorganic poly(3-hexylthiophene) (P3HT):CdSe nanowire heterojunction photodetectors are first demonstrated on silicon substrates, exhibiting a greatly enhanced photocurrent, a fast response, and a recovery time shorter than 0.1 s. Flexible hybrid photodetectors with excellent mechanical flexibility and stability are also fabricated on both poly(ethylene terephthalate) (PET) substrates and printing paper. The flexible devices are successfully operated under bending up to almost 180° and show an extremely high on/off switching ratio (larger than 500), a fast time response (about 10 ms), and excellent wavelength-dependence, which are very desirable properties for its practical application in high-frequency or high-speed flexible electronic devices.
Co-reporter:Gui Chen;Zhe Liu;Bo Liang;Gang Yu;Zhong Xie;Hongtao Huang;Bin Liu;Xianfu Wang;Di Chen;Ming-Qiang Zhu
Advanced Functional Materials 2013 Volume 23( Issue 21) pp:
Publication Date(Web):
DOI:10.1002/adfm.201370103
Co-reporter:Qiufan Wang, Xianfu Wang, Bin Liu, Gang Yu, Xiaojuan Hou, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2013 vol. 1(Issue 7) pp:2468-2473
Publication Date(Web):18 Dec 2012
DOI:10.1039/C2TA01283A
Portable electronic devices which are ultrathin, lightweight and even able to roll-up have attracted much attention. Herein, we report the design of flexible all-solid-state symmetric supercapacitors by using two NiCo2O4 nanowire arrays supported on Ni foams as the electrodes. The as-fabricated symmetric supercapacitors have excellent electrochemical performance with a high cell areal capacitance of 161 mF cm−2 at 1 mA cm−2. Good electrochemical performance stability over 3000 cycles was obtained even when the device was under harsh mechanical conditions including both twisted and bent states. As-fabricated all-solid-state supercapacitors could be charged and power a commercial light-emitting-diode, demonstrating their feasibility as an efficient energy storage component and self-powered micro/nano-system. In addition, we were able to grow NiCo2O4 nanowire arrays on many kinds of flexible substrates, including nickel foam, carbon cloth, Ti foil and polytetrafluoroethylene tape. Our work here opens up opportunities for the device configuration for energy-storage devices in the future wearable electronic area and many other flexible, lightweight and high performance functional nanoscale devices.
Co-reporter:Lijing Wang, Bin Liu, Sihan Ran, Liming Wang, Lina Gao, Fengyu Qu, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2013 vol. 1(Issue 6) pp:2139-2143
Publication Date(Web):30 Nov 2012
DOI:10.1039/C2TA00125J
Manganese-based oxides have been proven to be promising materials for applications in high voltage and high energy density Li-ion batteries. In this work, by using hydrothermally synthesized β-MnO2 nanorods as the templates, we prepared single-crystalline CoMn2O4 nano/submicrorods with diameters of about 100 nm and lengths up to tens of micrometers. The electrochemical tests showed that the CoMn2O4 products have a reversible capacity of 512 mA h g−1 at a current density of 200 mA g−1 with a coulombic efficiency of 98% after 100 cycles. A specific capacity of about 400 mA h g−1 was obtained even at a current density as high as 1000 mA g−1, exhibiting a high reversibility and a good capacity retention. This study suggests that CoMn2O4 nano/submicrorods are promising anode materials for high performance lithium-ion batteries.
Co-reporter:Zhe Liu, Bo Liang, Gui Chen, Gang Yu, Zhong Xie, Lina Gao, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2013 vol. 1(Issue 1) pp:131-137
Publication Date(Web):22 Oct 2012
DOI:10.1039/C2TC00055E
The ternary oxides, Zn2GeO4 and In2Ge2O7 nanowires, are promising n-type semiconductors with outstanding transport properties for high performance electronic devices. By using the direct contact printing process, we reported the assembly of horizontally aligned Zn2GeO4 and In2Ge2O7 nanowire arrays to be used as building blocks for high performance multi-channel field-effect transistors. The as-fabricated multi-channel transistors exhibited higher voltage stability and repeatability than their single nanowire based counterparts. The effective mobilities of the multi-channel field-effect transistors were calculated to be 25.44 cm2 V−1 s−1 and 11.9 cm2 V−1 s−1, comparable to the single-channel FETs. The as-fabricated multi-channel transistors were also used as high performance photodetectors, exhibited a high sensitivity to ultraviolet light illumination with a photoconductive gain and quantum efficiency as high as 1.034 × 105 and 1.032 × 107% for Zn2GeO4 nanowires and 2.58 × 105 and 2.617 × 107% for In2Ge2O7 nanowires.
Co-reporter:Jing Xu;Hui Wu;Chen Xu;Hongtao Huang;Dr. Linfeng Lu; Guqiao Ding;Dr. Huili Wang; Dongfang Liu; Guozhen Shen; Dongdong Li; Xiaoyuan Chen
Chemistry - A European Journal 2013 Volume 19( Issue 20) pp:6451-6458
Publication Date(Web):
DOI:10.1002/chem.201204571
Abstract
High capacitance and high output voltage are two important research focuses of electrochemical supercapacitors. Herein we present two novel designs (laminated and tandem) of coin-cell supercapacitors based on a textile coated with active material. The fabric electrodes were prepared by dipping the non-woven cloth into a dispersion of carbon nanotubes and subsequent MnO2 electrodeposition. In the lamination configuration, several pieces of active-material-coated cloth were laminated to construct individual electrodes that enable fold-increased areal capacitances and excellent cycling stability. In the tandem structure, individual cells with solid-state electrolyte (polyvinyl alcohol/H3PO4) sandwiched between the fabric electrodes were stacked together to form a single device. The assembled device composed by ten unit cells was demonstrated to drive four LED digital screens in series with 10 V output.
Co-reporter:Bin Liu, Jun Zhang, Xianfu Wang, Gui Chen, Di Chen, Chongwu Zhou, and Guozhen Shen
Nano Letters 2012 Volume 12(Issue 6) pp:3005-3011
Publication Date(Web):May 18, 2012
DOI:10.1021/nl300794f
Flexible electronics is an emerging and promising technology for next generation of optoelectronic devices. Herein, hierarchical three-dimensional ZnCo2O4 nanowire arrays/carbon cloth composites were synthesized as high performance binder-free anodes for Li-ion battery with the features of high reversible capacity of 1300–1400 mAh g–1 and excellent cycling ability even after 160 cycles with a capacity of 1200 mAh g–1. Highly flexible full batteries were also fabricated, exhibiting high flexibility, excellent electrical stability, and superior electrochemical performances.
Co-reporter:Bin Liu, Zhuoran Wang, Yuan Dong, Yuguang Zhu, Yue Gong, Sihan Ran, Zhe Liu, Jing Xu, Zhong Xie, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 vol. 22(Issue 18) pp:9379-9384
Publication Date(Web):02 Apr 2012
DOI:10.1039/C2JM16781F
We reported the fabrication of a highly flexible, sensitive, and excellent reproducible photo-detector based on flexible nanoparticle-assembled ZnO cloth, which was synthesized via a carbon cloth templated hydrothermal method. The conductance of the device increased more than 600 times after UV irradiation. The response time and decay time were found to be around 3.2 s and 2.8 s, respectively, indicating fast photoresponse characteristics for the ZnO cloth photodetector. Besides, the free-standing ZnO cloth can be easily thrown into the wastewater solution and used as a high performance recyclable photocatalyst under light irradiation, which can photodegrade organic dyes such as methylene blue (MB) within a short time of 40 min. The ZnO cloth can be used repeatedly without any weight loss. Our work here opens up opportunities for the fabrication of many other flexible, lightweight, foldable, portable and high performance functional devices.
Co-reporter:Hongtao Huang, Bo Liang, Zhe Liu, Xianfu Wang, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 vol. 22(Issue 27) pp:13428-13445
Publication Date(Web):01 May 2012
DOI:10.1039/C2JM31679J
Metal oxide nanowires are promising building blocks for thin film transistors due to their one-dimensional geometry in nanoscale, high crystalline nature, and excellent optical and electrical properties. In the past decade, intensive research interest has been drawn to metal oxide nanowire transistors, and various metal oxide nanowires like ZnO, In2O3, and SnO2 have been fabricated into thin film transistors to study their electrical properties and the characteristics as transistor active channels. Much effort has been paid to promote the performance of metal oxide nanowire transistors, and expand the application areas covering from sensing devices, transparent and flexible electronics, to memories and integrated logic circuits. In this review, we highlight the state-of-art progress in metal oxide nanowire transistors, with an emphasis on basic properties and performances. We summarize the characteristics of transistors based on different metal oxide nanowires, the strategies to improve the performance, and various application fields. Finally we present an outlook on the future development of metal oxide nanowire transistors, including the study of material properties, the design of device structures and the development of applications.
Co-reporter:Di Chen, Zhe Liu, Bo Liang, Xianfu Wang and Guozhen Shen
Nanoscale 2012 vol. 4(Issue 10) pp:3001-3012
Publication Date(Web):20 Mar 2012
DOI:10.1039/C2NR30445G
With the features of high mobility, a high electric on/off ratio and excellent transparency, metal oxide nanowires are excellent candidates for transparent thin-film transistors, which is one of the key technologies to realize transparent electronics. This article provides a comprehensive review of the state-of-the-art research activities that focus on transparent metal oxide nanowire transistors. It begins with the brief introduction to the synthetic methods for high quality metal oxide nanowires, and the typical nanowire transfer and printing techniques with emphasis on the simple contact printing methodology. High performance transparent transistors built on both single nanowires and nanowire thin films are then highlighted. The final section deals with the applications of transparent metal oxide nanowire transistors in the field of transparent displays and concludes with an outlook on the current perspectives and future directions of transparent metal oxide nanowire transistors.
Co-reporter:Zhong Xie, Lina Gao, Bo Liang, Xianfu Wang, Gui Chen, Zhe Liu, Junfeng Chao, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 vol. 22(Issue 37) pp:19904-19910
Publication Date(Web):13 Aug 2012
DOI:10.1039/C2JM33622G
By using electrochemical activated FTO glass as both a substrate and catalyst, we developed a facile and fast method to fabricate a WO3·2H2O thin film with a thickness of ∼100 nm. Due to the specific layered crystal structure of the dihydrated phase and the good contact with the transparent conductive oxides (TCOs) layer, the as-prepared WO3·2H2O thin film achieved a fast coloration/bleaching response speed (tc,90% = 3.2 s, tb,90% = 1.2 s), excellent cyclic stability, wide optical modulation range up to 53.8% and a high coloration efficiency of 107.8 cm2 C−1. A solid-state electrochromic device with a size of 5 cm × 5 cm was also fabricated, exhibiting high transparency contrast and good reversibility between the bleached and colored states.
Co-reporter:Liming Wang, Bin Liu, Sihan Ran, Hongtao Huang, Xianfu Wang, Bo Liang, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 vol. 22(Issue 44) pp:23541-23546
Publication Date(Web):21 Sep 2012
DOI:10.1039/C2JM35617A
Highly symmetric Co3O4 hexapods assembled by numerous porous nanorods were successfully grown on copper foil through a facile hydrothermal method followed by thermal treatment. The as-prepared Co3O4 hexapods were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. Directly configured as binder-free anodes for lithium-ion batteries, the as-grown Co3O4 hexapods on copper foil exhibited a very high reversible capacity of 800 mA h g−1 at 100 mA g−1 and 440 mA h g−1 at 500 mA g−1 even after 40 cycles. The good electrochemical performance is attributed to the unique porous structure of the Co3O4 hexapods and the good contact with Cu foil. The performance could be further improved by carbon coating, exhibiting an enhanced reversible capacity of 1001 mA h g−1 after even 40 cycles. The synthetic strategy holds the potential for large scale production of other transition metal oxides as high performance anodes for lithium-ion batteries.
Co-reporter:Xianfu Wang, Hongtao Huang, Bin Liu, Bo Liang, Chao Zhang, Qin Ji, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 vol. 22(Issue 12) pp:5330-5335
Publication Date(Web):05 Jan 2012
DOI:10.1039/C1JM14551G
3-D straw-bundle-like Zn2SiO4 architectures assembled from numerous radial nanowires were synthesized by a simple thermal evaporation method using ZnCl2 powder as reactant. The growth process was studied in detail and a “nanorods-to-straw-bundles-to-spheres” mechanism was proposed for the nanostructures synthesized from the vapor process. The application of the Zn2SiO4 straw bundles for the removal of toxic metal ions in water, FeIII and CdII in this case, was investigated and the results indicate that the amount of FeIII and CdII adsorbed onto the surface of the Zn2SiO4 straw bundles increased with the increase of pH values, and the Zn2SiO4 nanostructures showed better removal capacity for FeIII ions than CdII ions.
Co-reporter:Zhuoran Wang, Sihan Ran, Bin Liu, Di Chen and Guozhen Shen
Nanoscale 2012 vol. 4(Issue 11) pp:3350-3358
Publication Date(Web):02 Apr 2012
DOI:10.1039/C2NR30440F
A multilayer TiO2 nanorod-assembled cloth/nanorod array based electrode was fabricated by transferring different layers of TiO2 nanorod-assembled cloth (TNRC) onto nanorod array grown on the conducting FTO substrate (titania nanorod, TNR). Combining the superior electron transport characteristics of TNR and outstanding optical properties of TNRC, the nanostructured electrode composed of two layers of TNRC meets the optimized design for high quality dye-sensitized solar cells (DSCs) and self-powered UV detectors. The highest efficiency of 4.02% for DSC under AM 1.5 was achieved with a high short circuit current density of 9.81 mA cm−2, which was proved to be owing to the enhanced dye anchoring, light scattering and reduced charge recombination. For the photoelectrochemical (PEC) UV detector, the highest quantum efficiency of over 46% was obtained and a high photocurrent response of 0.271 mA cm−2 was observed, together with the excellent self-powered, fast response and “visible blind” characteristics. A perfect linear response to the changed low-power signal indicates great potential for practical applications.
Co-reporter:Qiufan Wang, Bin Liu, Xianfu Wang, Sihan Ran, Liming Wang, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 vol. 22(Issue 40) pp:21647-21653
Publication Date(Web):24 Aug 2012
DOI:10.1039/C2JM34705A
Urchin-like NiCo2O4 nanostructures were synthesized on a large scale via a simple hydrothermal method free of any template and catalyst. As-synthesized NiCo2O4 urchins have uniform diameters of 5 μm with numerous small nanorods radially grown from the center. Typical nanorods have diameters of 100–200 nm and lengths of about 2 μm. Studies found that urea plays an important role to determine the morphology of the products and a “rods-to-straw-bundles-to-urchins” mechanism was proposed. With a porous structure and a large surface area of 99.3 m2 g−1, the prepared NiCo2O4 urchins exhibited superior specific capacitance of 1650 and 1348 F g−1 at current densities of 1 and 15 A g−1, respectively. The capacitance loss after 2000 cycles is only 9.2% at the current density of 8 A g−1, indicating their excellent cycling stability. Photoelectrochemical cells were also fabricated on the urchin-like NiCo2O4 nanostructures with the features of fast photocurrent response and excellent stability. A high photocurrent response of about 70 μA cm−2 was observed.
Co-reporter:Xianfu Wang, Zhong Xie, Hongtao Huang, Zhe Liu, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 vol. 22(Issue 14) pp:6845-6850
Publication Date(Web):28 Feb 2012
DOI:10.1039/C2JM16523F
By using thermal-evaporation-grown single crystalline ZnS nanowires as the active materials, several kinds of high performance sensors, including gas sensors, thermistors, and ultraviolet (UV) light sensors, were fabricated. ZnS nanowire-based gas sensors show high sensitivity, fast response and recovery times, and high selectivity, and can be used to detect acetone and ethanol down to 500 ppb level. The thermal index (B) of the device is about 3100 K, indicating it is suitable for fabricating high performance thermistors. The high sensitivity, good stability, and fast response toward UV light imply that ZnS nanowires (NWs) are particularly valuable for UV-light photodetectors.
Co-reporter:Sihan Ran, Yuguang Zhu, Hongtao Huang, Bo Liang, Jing Xu, Bin Liu, Jun Zhang, Zhong Xie, Zhuoran Wang, Jinhua Ye, Di Chen and Guozhen Shen
CrystEngComm 2012 vol. 14(Issue 9) pp:3063-3068
Publication Date(Web):23 Feb 2012
DOI:10.1039/C2CE06308E
3D flower-like Ni(OH)2 architectures including α- and β-Ni(OH)2 phases, respectively, have been successfully synthesized via a facile microwave-assisted hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2 adsorption, respectively. The possible mechanism of Ni(OH)2 architectures has been discussed and found that the reaction temperature plays a critical role in the formation of two kinds of products. Specifically, flower-like β-Ni(OH)2 with monolayer petals and α-Ni(OH)2 with bilayer petals were prepared at 120 °C and 150 °C, respectively. It was suggested that both architectures hold the advantages of large surface-exposure areas and can be readily separated for wastewater treatment due to their particular surface microstructures. Adsorption results showed that both samples exhibited significantly different selectivities for cationic/anionic dyes such as methylene blue (MB) and acid fuschine in aqueous solutions. The hydrophilic properties of two samples were investigated at room temperature. Furthermore, the relationships among the adsorption abilities, the hydrophilic properties and their applications in wastewater treatment of Ni(OH)2 architectures have been discussed in detail.
Co-reporter:Junfeng Chao, Xin Xu, Hongtao Huang, Zhe Liu, Bo Liang, Xianfu Wang, Sihan Ran, Di Chen and Guozhen Shen
CrystEngComm 2012 vol. 14(Issue 20) pp:6654-6658
Publication Date(Web):26 Jun 2012
DOI:10.1039/C2CE25089F
SnO2 has been confirmed to be a potential sensor to many toxic volatile gases. We report here the synthesis of porous SnO2 nanoflowers by in situ oxidization of SnS and SnS2 precursors with similar morphologies. The as-synthesized SnO2 products were characterized by FESEM, XRD, TEM, UV-vis spectrometry, fluorescence spectrometry and the nitrogen adsorption–desorption technique. Configured as resistor-type chemical sensors, the as-synthesized SnO2 products exhibited excellent sensitivity and fast response/recovery times towards different gases including ethanol, methanol, methanal and acetone. After Pt nanoparticles were loaded, their sensing properties were dramatically increased, indicating their promising applications in detecting toxic volatile organic materials.
Co-reporter:Junfeng Chao, Zhong Xie, XianBao Duan, Yuan Dong, Zhuoran Wang, Jing Xu, Bo Liang, Bin Shan, Jinhua Ye, Di Chen and Guozhen Shen
CrystEngComm 2012 vol. 14(Issue 9) pp:3163-3168
Publication Date(Web):28 Feb 2012
DOI:10.1039/C2CE06586J
By using a facile and template-free polyol refluxing process, we reported the successful synthesis of porous SnS and SnS2 architectures on a large scale. The as-synthesized samples were characterized by using XRD, SEM, TEM, UV-vis DRS, Raman and N2 adsorption–desorption analyses. Studies revealed that the as-synthesized SnS and SnS2 products mainly consist of porous flower-like microstructures with reasonable BET surface areas of 66 m2 g−1 and 33 m2 g−1, respectively. Photocatalytic properties of trace amounts of samples were investigated by photodegradation of MB and RhB under visible light irradiation. The photoelectrochemical properties of both samples were also studied by configuring the samples as photoelectrochemical (PEC) cells, exhibiting excellent photosensitivity and response with greatly enhanced Ion/off as high as 1.4 × 103, three orders of magnitude higher than previous work. The results indicate the potential applications of the SnSx nanostructures in visible-light-driven photocatalysts, high response photodetectors and other optoelectronic nanodevices.
Co-reporter:Bin Liu, Jing Xu, Sihan Ran, Zhuoran Wang, Di Chen and Guozhen Shen
CrystEngComm 2012 vol. 14(Issue 14) pp:4582-4588
Publication Date(Web):27 Mar 2012
DOI:10.1039/C2CE25278C
By using porous ZnO nanosheets, obtained from a rapid one-step polyol refluxing method, as the active material, we reported the fabrication of high performance photodetectors, photocatalysts, and gas sensors. The as fabricated photodetectors exhibited the features of high photocurrent, enhanced stability, and reproducible characteristics with the photo-to-dark current ratio as high as 1.6 × 103. The photocatalytic properties were also investigated by the photo-degradation of methylene blue under UV light irradiation. The as-synthesized porous ZnO nanosheets were able to decompose methylene blue within 20 min, which is more than twice as fast as that of ZnO nanoparticles and nanospheres. Finally, the gas sensing performance of the porous ZnO nanosheets for detecting ethanol was investigated, also revealing greater enhanced performance compared with other ZnO nanostructures.
Co-reporter:Guozhen Shen;Jing Xu;Xianfu Wang;Hongtao Huang ;Di Chen
Advanced Materials 2011 Volume 23( Issue 6) pp:771-775
Publication Date(Web):
DOI:10.1002/adma.201003474
Co-reporter:Jing Xu, Yansong Li, Hongtao Huang, Yuguang Zhu, Zhuoran Wang, Zhong Xie, Xianfu Wang, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2011 vol. 21(Issue 47) pp:19086-19092
Publication Date(Web):27 Oct 2011
DOI:10.1039/C1JM13350K
Using a tin-oleate complex as the precursor and the capping agent, we successfully synthesized ultrafine SnO2 nanospike arrays with diameter 6–15 nm and length 150 nm, growing along the [001] direction from a simple hydrothermal route. The as-obtained SnO2 products were characterized by X-ray powder diffraction, scanning electronic microscopy, transmission electron microscopy, UV-vis absorption spectrum, photoluminescence and Raman spectroscopy. As-synthesized SnO2 nanospike arrays exhibited improved gas sensing performance as compared to bulk SnO2 due to the small grain size-distribution and specific surface properties. The detection limits of the sensor were found to be down to 0.5 ppm for acetone, ethanol and 1.0 ppm for methanol with response time as short as 5 s.
Co-reporter:Yansong Li, Jing Xu, Junfeng Chao, Di Chen, Shuxin Ouyang, Jinhua Ye and Guozhen Shen
Journal of Materials Chemistry A 2011 vol. 21(Issue 34) pp:12852-12857
Publication Date(Web):22 Jul 2011
DOI:10.1039/C1JM11356A
With greatly enhanced surface-to-volume ratios, one-dimensional (1-D) nanostructures are believed to be able to deliver better performance as chemical sensors. In this paper, by using a hydrothermal-annealing process, we reported the synthesis of porous In2O3 nanobelts with a high aspect ratio. By annealing hydrothermally-synthesized single crystalline ultralong InOOH nanobelts, single crystalline porous In2O3 nanobelts with an aspect ratio larger than 100 are obtained on a large scale. The gas sensing properties of the as-prepared porous In2O3 nanobelts were investigated, and they can detect different chemicals (methanol, ethanol, and acetone) down to ppb level. The results also showed that the nanobelts exhibited excellent gas sensing performance in terms of high sensitivity, low detection limit, fast response and recovery times, and sensing selectivity.
Co-reporter:Di Chen, Jing Xu, Bo Liang, Xianfu Wang, Po-Chiang Chen, Chongwu Zhou and Guozhen Shen
Journal of Materials Chemistry A 2011 vol. 21(Issue 43) pp:17236-17241
Publication Date(Web):26 Sep 2011
DOI:10.1039/C1JM13579A
Ternary oxides have the advantages of tuning their physical properties by varying the proportion of each component, thus attracting great research attention in recent years. As an example, we demonstrated in this work the investigation on the electronic transport, surface wettability and chemical sensing properties of zigzag Zn2SnO4 nanowires, which were synthesized from a thermal evaporation method. Structural characterizations reveal that these nanowires are single crystals with average diameters of ∼100 nm and grow along the [11] direction. Single nanowire-based field effect transistor was fabricated, showing an on/off ratio of 104 and a device mobility of 17.2 cm2 (V s)−1. Besides, these Zn2SnO4 nanowire-based devices showed a substantial increase in conductance upon exposure to UV light. Thin films of the zigzag Zn2SnO4 nanowires were configured as high performance sensors to detect hosts of chemicals with detection limits down to the 1 ppm level, especially for ethanol and acetone, implying promising applications in detecting toxic volatile organic compounds.
Co-reporter:Di Chen, Jing Xu, Zhong Xie, and Guozhen Shen
ACS Applied Materials & Interfaces 2011 Volume 3(Issue 6) pp:2112
Publication Date(Web):May 4, 2011
DOI:10.1021/am2003312
Self-assembly of one-dimensional nanoscale building blocks into functional 2-D or 3-D complex superstructures has stimulated a great deal of interest. We report the synthesis and characterization of nanopolyhedrons assembled from ultrathin SnO2 nanowires based on the sodium dodecyl sulfate (SDS)-assisted hydrothermal process. As-synthesized SnO2 nanopolyhedrons have uniform diameters around 300 nm and are self-assembled by numerous ultrathin SnO2 nanowires with diameters of 5–10 nm. The growth mechanism was also studied by investigating the samples synthesized at different reaction time. Thin films of the assembled SnO2 nanopolyhedrons were configured as high performance sensors to detect methanol, ethanol, and acetone, which exhibited 1 ppm sensitivity, very fast response and recovery times (several seconds for different gases with concentrations of 1–200 ppm) to all the target gases and highly selective detection to acetone.Keywords: assembly; chemical sensor; hydrothermal; nanopolyhedron; nanowires; SnO2
Co-reporter:Jing Xu, Yuguang Zhu, Hongtao Huang, Zhong Xie, Di Chen and Guozhen Shen
CrystEngComm 2011 vol. 13(Issue 7) pp:2629-2635
Publication Date(Web):14 Feb 2011
DOI:10.1039/C0CE00868K
Using a zinc-oleate complex as an efficient self-templated precursor, we report the synthesis of ZnO nanowires and olive-shaped nanorods with growth directions along the (0001) planes via a mild hydrothermal route. As-obtained ZnO products were characterized by using X-ray powder diffraction, scanning electronic microscopy, transmission electron microscopy, UV-vis absorption spectroscopy and photoluminescence spectroscopy. Compared to ZnO nanorods, long nanowires show enhanced photoactivity for methylene blue degradation under UV light irradiation. The surface wettability of the samples was also measured and the hydrophobicity of ZnO long nanowires and the hydrophilicity of ZnO olive-shaped nanorods were observed. The gas sensitivity for acetone and ethanol of both ZnO nanorods and nanowires was measured.
Co-reporter:Zhong Xie, Yuguang Zhu, Jing Xu, Hongtao Huang, Di Chen and Guozhen Shen
CrystEngComm 2011 vol. 13(Issue 21) pp:6393-6398
Publication Date(Web):22 Aug 2011
DOI:10.1039/C1CE05579H
Pure porous WO3 products consisting of 10–20 nm nanoparticles have been synthesized by controlling the hydrolysis of WCl6 in ethanol solution with the assistance of polystyrene (PS) microspheres at room temperature. The products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) surface area and diffuse reflectance spectroscopy. The photocatalytic and gas-sensing properties of the porous WO3 samples were studied in detail. With large surface areas, these porous WO3 products exhibit both strong adsorption abilities and high degradation activities for methylene blue (MB) under visible light irradiation. And they also exhibit high sensitivity to organic gases (acetone, methanol, ethanol and formaldehyde), especially good selectivity to acetone at low concentration (0.5–5 ppm).
Co-reporter:Di Chen, Zhe Liu, Xianfu Wang, Bo Liang, Jing Xu, Hongtao Huang, Zhong Xie and Guozhen Shen
CrystEngComm 2011 vol. 13(Issue 24) pp:7305-7310
Publication Date(Web):13 Oct 2011
DOI:10.1039/C1CE05666B
Hierarchical Zn3P2 nanoribbon–ZnS nanowire heterostructures were synthesized by simple thermal evaporation of the mixture of ZnS and InP powders. Studies found that the synthesized hierarchical heterostructures consisted of single crystalline Zn3P2 nanoribbons with numerous single crystalline [0001]-oriented ZnS nanowires grown perpendicular to the Zn3P2 nanoribbons. The growth mechanism of the hierarchical heterostructures was investigated in detail by studying the intermediate samples synthesized at different times. Low-temperature cathodoluminescence properties of the heterostructures were investigated, where two emission bands centered at 600 nm and 790 nm were observed, corresponding to the defect-related emission of ZnS and band gap emission of Zn3P2, respectively. Single heterostructure-based devices were also fabricated to study their photoconducting properties, showing decent responses to lights with different wavelengths.
Co-reporter:Shi Xiong, Jing Xu, Di Chen, Rongming Wang, Xianluo Hu, Guozhen Shen and Zhong Lin Wang
CrystEngComm 2011 vol. 13(Issue 23) pp:7114-7120
Publication Date(Web):04 Oct 2011
DOI:10.1039/C1CE05569K
Hematite (α-Fe2O3) is a thermodynamically stable crystallographic phase of iron oxide and has attractive applications in many areas. By using a simple hydrothermal method, we synthesized smooth hematite microcubes and porous hematite microcubes. The as-synthesized microcubes have uniform edge lengths of about 1 μm. The magnetic, electrochemical properties and gas sensing performance to some organic gases were investigated, revealing the potential applications in various fields. By tuning the experimental parameters, such as source and solvent, we are able to tunably produce goethite (FeOOH) nanowires, and hematite nanoparticles, nanorods, and nanoplatelets and the formation mechanism was also discussed.
Co-reporter:Zhuoran Wang, Heng Wang, Bin Liu, Wenzhe Qiu, Jun Zhang, Sihan Ran, Hongtao Huang, Jing Xu, Hongwei Han, Di Chen, and Guozhen Shen
ACS Nano 2011 Volume 5(Issue 10) pp:8412
Publication Date(Web):September 23, 2011
DOI:10.1021/nn203315k
Flexible and transferable TiO2 nanorods cloths (TNRCs) were synthesized from a fast and catalyst-free microwave heating route by using carbon cloth as an efficiently sacrificial template. The as-synthesized TNRCs were assembled by numerous aligned TiO2 nanorods with diameters of about 100 nm. The good transferability and flexibility make it possible to be transferred to any substrate for further device applications. As an example, we transferred the TNRCs to a FTO substrate to make dye-sensitized solar cells, which exhibited an improved efficiency of around 2.21% assisted by TiCl4 treatment. The transferable TNRCs were also configured as high-performance photodetectors. Illuminated by UV light with a wavelength of 365 nm, the current was found significantly enhanced, and an IUV/Idark of about 60, a rise time of nearly 1.4 s, and a decay time of 6.1 s were obtained. Moreover, they were also configured as flexible and recyclable photocatalysts with good photocatalytic performance for the degradation of methylene blue solution under UV light irradiation.Keywords: dye-sensitized solar cells; nanorods; photocatalysts; photodetectors; TiO2
Co-reporter:Guozhen Shen, Bo Liang, Xianfu Wang, Po-Chiang Chen, and Chongwu Zhou
ACS Nano 2011 Volume 5(Issue 3) pp:2155
Publication Date(Web):February 17, 2011
DOI:10.1021/nn103358y
Helical inorganic nanostructures have received great attention due to their unique structures that could be interesting for both fundamental research and nanodevice applications. Using a tube-in-tube laser ablation chemical vapor deposition (CVD) method with gold nanoparticles as the catalysts, we reported the synthesis of self-assembled kinked In2O3 nanospirals and multikinked nanowires. As-synthesized nanostructures showed ultrafast photoinduced reversible wettability switching behavior from hydrophobic (132.7°) to superhydrophilic (0°) within 14 min. Single kinked In2O3 nanostructure-based field-effect transistors were fabricated, and mobilities higher than 200 cm2/(V·s) were obtained, revealing good opportunity in fabricating high-performance electronic and optoelectronic devices.Keywords: In2O3; kinked; nanospirals; nanowires; transistors
Co-reporter:Guozhen Shen, Bo Liang, Xianfu Wang, Hongtao Huang, Di Chen, and Zhong Lin Wang
ACS Nano 2011 Volume 5(Issue 8) pp:6148
Publication Date(Web):July 12, 2011
DOI:10.1021/nn2014722
Ultrafine one-dimensional (1-D) semiconducting nanostructures with diameters below 10 nm are attracting great research attention. Using a laser-ablation chemical vapor deposition (CVD) method, we reported the synthesis of single-crystal In2O3 nanowires with diameter below 4 nm. The as-synthesized ultrathin In2O3 nanowires act as the ultrathin branches of hierarchical In2O3 nanostructures and show fast photoinduced switching surface wettability behaviors, and the contact angle decreased from 134.3 to 0° in 10 min. Transparent thin-film transistors (TTFTs) were fabricated using the as-synthesized product, and the device conductance was 1–2 orders higher than the average conductance of the In2O3 single nanowire devices, revealing good opportunity in transparent electronics.Keywords: In2O3; nanowires; transistors; transparent; ultrathin
Co-reporter:Guozhen Shen and Di Chen
Journal of Materials Chemistry A 2010 vol. 20(Issue 48) pp:10888-10893
Publication Date(Web):13 Oct 2010
DOI:10.1039/C0JM02189J
Aligned nanowires are likely to be more suitable for applications in electronics and optoelectronics than randomly distributed nanowires. In this paper, by using a fast-heating-vapor-trapping (FHVT) method, we successfully synthesized aligned In2O3 nanobelt arrays on an Au-coated silicon substrate without the use of any templates. Studies found that the nanobelts exhibited unique bi-crystalline structures consisting of two single crystalline In2O3 nanobelts, most of which have the same growth direction along the [100] plane. Field-effect transistors were fabricated on the basis of single In2O3 nanowires and they exhibited typical n-type transistor performance, which showed a decent response to UV light exposure.
Co-reporter:Guozhen Shen ;Di Chen
The Journal of Physical Chemistry C 2010 Volume 114(Issue 49) pp:21088-21093
Publication Date(Web):November 17, 2010
DOI:10.1021/jp107213q
Transparent zinc oxide nanowires orderly decorated with silver nanoparticles/nanorods were synthesized by thermal evaporating of metallic zinc powders at 550 °C by using Ag nanoparticles-coated silicon as the substrate. As-obtained ZnO nanowires are single crystals with the preferred growth directions along the [0001] plane, with Ag nanoparticles/nanorods orderly attached to the whole length of the nanowires. Single ZnO-nanowire-based devices were fabricated, and it is revealed that as-synthesized Ag-nanoparticle/nanorods-decorated ZnO nanowires are transparent conductors with resistivities down to 6.8 × 10−4 Ωcm and failure-current density up to 4.5 × 107 A/cm2 because of the single-crystalline metallic structure.
Co-reporter:Di Chen;Jing Xu
Frontiers of Optoelectronics 2010 Volume 3( Issue 3) pp:217-227
Publication Date(Web):2010 September
DOI:10.1007/s12200-010-0110-0
Transparent electronics has attracted great research efforts in recent years due to its potential to make significant impact in many area, such as next generation displays, ultraviolet (UV) detectors, solar cells, charge-coupled devices (CCDs), and so on. Central to the realization of transparent electronics is the development of high performance fully transparent thin-film transistors (TFTs). One-dimensional (1-D) nanostructures have been the focus of current researches due to their unique physical properties and potential applications in nanoscale electronics and optoelectronics. Among 1-D nanostructures, transparent metal oxide nanowires are one of the best candidates to make fully transparent TFTs. We provide in this paper the most recent development on the fabrication of fully transparent TFT using metal oxide nanowires as the device elements. First, the review article gives a general introduction about the development of transparent electronics using different kinds of materials as the devices elements, including organic semiconductors, metal oxide thin films, and metal oxide nanowires. Second, the growth of metal oxide nanowires using vapor phase methods governed by two different growth mechanisms: vaporsolid mechanism and vapor-liquid-solid mechanism, respectively, are described. Third, the fabrication of transparent and flexible TFTs using different metal oxides nanowires is comprehensively described. In conclusion, the challenges and prospects for the future are discussed.
Co-reporter:Yutao Han, Xiang Wu, Guozhen Shen, Benjamin Dierre, Lihong Gong, Fengyu Qu, Yoshio Bando, Takashi Sekiguchi, Fabbri Filippo and Dmitri Golberg
The Journal of Physical Chemistry C 2010 Volume 114(Issue 18) pp:8235-8240
Publication Date(Web):April 13, 2010
DOI:10.1021/jp100942m
Large-scale novel core−shell microspheres of SnO2 have been synthesized through a simple solution method at 200 °C. Morphologies, microstructures, and compositions of the products are investigated by X-ray powder diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Results indicate that the SnO2 microspheres are core−shell structures with an average diameter of 6 μm and an average shell thickness of 200 nm. A growth mechanism and the cathodoluminescence properties of these novel structures are presented.
Co-reporter:Guozhen Shen;Di Chen
Frontiers of Optoelectronics 2010 Volume 3( Issue 2) pp:125-138
Publication Date(Web):2010 June
DOI:10.1007/s12200-010-0001-4
One-dimensional (1-D) nanostructures have been the focus of current researches due to their unique physical properties and potential applications in nanoscale electronics and optoelectronics. They address and overcome the physical and economic limits of current microelectronic industry and will lead to reduced power consumption and largely increased device speed in next generation electronics and optoelectronics. This paper reviews the recent development on the device applications of 1-D nanostructures in electronics and optoelectronics. First, typical 1-D nanostructure forms, including nanorods, nanowires, nanotubes, nanobelts, and hetero-nanowires, synthesized from different methods are briefly discussed. Then, some nanoscale electronic and optoelectronic devices built on 1-D nanostructures are presented, including field-effect transistors (FETs), p-n diodes, ultraviolet (UV) detectors, light-emitting diodes (LEDs), nanolasers, integrated nanodevices, single nanowire solar cells, chemical sensors, biosensors, and nanogenerators. We then finalize the paper with some perspectives and outlook towards the fast-growing topics.
Co-reporter:Xianfu Wang, Zhong Xie, Hongtao Huang, Zhe Liu, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 - vol. 22(Issue 14) pp:NaN6850-6850
Publication Date(Web):2012/02/28
DOI:10.1039/C2JM16523F
By using thermal-evaporation-grown single crystalline ZnS nanowires as the active materials, several kinds of high performance sensors, including gas sensors, thermistors, and ultraviolet (UV) light sensors, were fabricated. ZnS nanowire-based gas sensors show high sensitivity, fast response and recovery times, and high selectivity, and can be used to detect acetone and ethanol down to 500 ppb level. The thermal index (B) of the device is about 3100 K, indicating it is suitable for fabricating high performance thermistors. The high sensitivity, good stability, and fast response toward UV light imply that ZnS nanowires (NWs) are particularly valuable for UV-light photodetectors.
Co-reporter:Zhe Liu, Bo Liang, Gui Chen, Gang Yu, Zhong Xie, Lina Gao, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2013 - vol. 1(Issue 1) pp:NaN137-137
Publication Date(Web):2012/10/22
DOI:10.1039/C2TC00055E
The ternary oxides, Zn2GeO4 and In2Ge2O7 nanowires, are promising n-type semiconductors with outstanding transport properties for high performance electronic devices. By using the direct contact printing process, we reported the assembly of horizontally aligned Zn2GeO4 and In2Ge2O7 nanowire arrays to be used as building blocks for high performance multi-channel field-effect transistors. The as-fabricated multi-channel transistors exhibited higher voltage stability and repeatability than their single nanowire based counterparts. The effective mobilities of the multi-channel field-effect transistors were calculated to be 25.44 cm2 V−1 s−1 and 11.9 cm2 V−1 s−1, comparable to the single-channel FETs. The as-fabricated multi-channel transistors were also used as high performance photodetectors, exhibited a high sensitivity to ultraviolet light illumination with a photoconductive gain and quantum efficiency as high as 1.034 × 105 and 1.032 × 107% for Zn2GeO4 nanowires and 2.58 × 105 and 2.617 × 107% for In2Ge2O7 nanowires.
Co-reporter:Zhong Xie, Lina Gao, Bo Liang, Xianfu Wang, Gui Chen, Zhe Liu, Junfeng Chao, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 - vol. 22(Issue 37) pp:NaN19910-19910
Publication Date(Web):2012/08/13
DOI:10.1039/C2JM33622G
By using electrochemical activated FTO glass as both a substrate and catalyst, we developed a facile and fast method to fabricate a WO3·2H2O thin film with a thickness of ∼100 nm. Due to the specific layered crystal structure of the dihydrated phase and the good contact with the transparent conductive oxides (TCOs) layer, the as-prepared WO3·2H2O thin film achieved a fast coloration/bleaching response speed (tc,90% = 3.2 s, tb,90% = 1.2 s), excellent cyclic stability, wide optical modulation range up to 53.8% and a high coloration efficiency of 107.8 cm2 C−1. A solid-state electrochromic device with a size of 5 cm × 5 cm was also fabricated, exhibiting high transparency contrast and good reversibility between the bleached and colored states.
Co-reporter:Yansong Li, Jing Xu, Junfeng Chao, Di Chen, Shuxin Ouyang, Jinhua Ye and Guozhen Shen
Journal of Materials Chemistry A 2011 - vol. 21(Issue 34) pp:NaN12857-12857
Publication Date(Web):2011/07/22
DOI:10.1039/C1JM11356A
With greatly enhanced surface-to-volume ratios, one-dimensional (1-D) nanostructures are believed to be able to deliver better performance as chemical sensors. In this paper, by using a hydrothermal-annealing process, we reported the synthesis of porous In2O3 nanobelts with a high aspect ratio. By annealing hydrothermally-synthesized single crystalline ultralong InOOH nanobelts, single crystalline porous In2O3 nanobelts with an aspect ratio larger than 100 are obtained on a large scale. The gas sensing properties of the as-prepared porous In2O3 nanobelts were investigated, and they can detect different chemicals (methanol, ethanol, and acetone) down to ppb level. The results also showed that the nanobelts exhibited excellent gas sensing performance in terms of high sensitivity, low detection limit, fast response and recovery times, and sensing selectivity.
Co-reporter:Qiufan Wang, Bin Liu, Xianfu Wang, Sihan Ran, Liming Wang, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 - vol. 22(Issue 40) pp:NaN21653-21653
Publication Date(Web):2012/08/24
DOI:10.1039/C2JM34705A
Urchin-like NiCo2O4 nanostructures were synthesized on a large scale via a simple hydrothermal method free of any template and catalyst. As-synthesized NiCo2O4 urchins have uniform diameters of 5 μm with numerous small nanorods radially grown from the center. Typical nanorods have diameters of 100–200 nm and lengths of about 2 μm. Studies found that urea plays an important role to determine the morphology of the products and a “rods-to-straw-bundles-to-urchins” mechanism was proposed. With a porous structure and a large surface area of 99.3 m2 g−1, the prepared NiCo2O4 urchins exhibited superior specific capacitance of 1650 and 1348 F g−1 at current densities of 1 and 15 A g−1, respectively. The capacitance loss after 2000 cycles is only 9.2% at the current density of 8 A g−1, indicating their excellent cycling stability. Photoelectrochemical cells were also fabricated on the urchin-like NiCo2O4 nanostructures with the features of fast photocurrent response and excellent stability. A high photocurrent response of about 70 μA cm−2 was observed.
Co-reporter:Liming Wang, Bin Liu, Sihan Ran, Hongtao Huang, Xianfu Wang, Bo Liang, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 - vol. 22(Issue 44) pp:NaN23546-23546
Publication Date(Web):2012/09/21
DOI:10.1039/C2JM35617A
Highly symmetric Co3O4 hexapods assembled by numerous porous nanorods were successfully grown on copper foil through a facile hydrothermal method followed by thermal treatment. The as-prepared Co3O4 hexapods were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. Directly configured as binder-free anodes for lithium-ion batteries, the as-grown Co3O4 hexapods on copper foil exhibited a very high reversible capacity of 800 mA h g−1 at 100 mA g−1 and 440 mA h g−1 at 500 mA g−1 even after 40 cycles. The good electrochemical performance is attributed to the unique porous structure of the Co3O4 hexapods and the good contact with Cu foil. The performance could be further improved by carbon coating, exhibiting an enhanced reversible capacity of 1001 mA h g−1 after even 40 cycles. The synthetic strategy holds the potential for large scale production of other transition metal oxides as high performance anodes for lithium-ion batteries.
Co-reporter:Jing Xu, Yansong Li, Hongtao Huang, Yuguang Zhu, Zhuoran Wang, Zhong Xie, Xianfu Wang, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2011 - vol. 21(Issue 47) pp:NaN19092-19092
Publication Date(Web):2011/10/27
DOI:10.1039/C1JM13350K
Using a tin-oleate complex as the precursor and the capping agent, we successfully synthesized ultrafine SnO2 nanospike arrays with diameter 6–15 nm and length 150 nm, growing along the [001] direction from a simple hydrothermal route. The as-obtained SnO2 products were characterized by X-ray powder diffraction, scanning electronic microscopy, transmission electron microscopy, UV-vis absorption spectrum, photoluminescence and Raman spectroscopy. As-synthesized SnO2 nanospike arrays exhibited improved gas sensing performance as compared to bulk SnO2 due to the small grain size-distribution and specific surface properties. The detection limits of the sensor were found to be down to 0.5 ppm for acetone, ethanol and 1.0 ppm for methanol with response time as short as 5 s.
Co-reporter:Di Chen, Jing Xu, Bo Liang, Xianfu Wang, Po-Chiang Chen, Chongwu Zhou and Guozhen Shen
Journal of Materials Chemistry A 2011 - vol. 21(Issue 43) pp:NaN17241-17241
Publication Date(Web):2011/09/26
DOI:10.1039/C1JM13579A
Ternary oxides have the advantages of tuning their physical properties by varying the proportion of each component, thus attracting great research attention in recent years. As an example, we demonstrated in this work the investigation on the electronic transport, surface wettability and chemical sensing properties of zigzag Zn2SnO4 nanowires, which were synthesized from a thermal evaporation method. Structural characterizations reveal that these nanowires are single crystals with average diameters of ∼100 nm and grow along the [11] direction. Single nanowire-based field effect transistor was fabricated, showing an on/off ratio of 104 and a device mobility of 17.2 cm2 (V s)−1. Besides, these Zn2SnO4 nanowire-based devices showed a substantial increase in conductance upon exposure to UV light. Thin films of the zigzag Zn2SnO4 nanowires were configured as high performance sensors to detect hosts of chemicals with detection limits down to the 1 ppm level, especially for ethanol and acetone, implying promising applications in detecting toxic volatile organic compounds.
Co-reporter:Guozhen Shen and Di Chen
Journal of Materials Chemistry A 2010 - vol. 20(Issue 48) pp:NaN10893-10893
Publication Date(Web):2010/10/13
DOI:10.1039/C0JM02189J
Aligned nanowires are likely to be more suitable for applications in electronics and optoelectronics than randomly distributed nanowires. In this paper, by using a fast-heating-vapor-trapping (FHVT) method, we successfully synthesized aligned In2O3 nanobelt arrays on an Au-coated silicon substrate without the use of any templates. Studies found that the nanobelts exhibited unique bi-crystalline structures consisting of two single crystalline In2O3 nanobelts, most of which have the same growth direction along the [100] plane. Field-effect transistors were fabricated on the basis of single In2O3 nanowires and they exhibited typical n-type transistor performance, which showed a decent response to UV light exposure.
Co-reporter:Xianfu Wang, Hongtao Huang, Bin Liu, Bo Liang, Chao Zhang, Qin Ji, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 - vol. 22(Issue 12) pp:NaN5335-5335
Publication Date(Web):2012/01/05
DOI:10.1039/C1JM14551G
3-D straw-bundle-like Zn2SiO4 architectures assembled from numerous radial nanowires were synthesized by a simple thermal evaporation method using ZnCl2 powder as reactant. The growth process was studied in detail and a “nanorods-to-straw-bundles-to-spheres” mechanism was proposed for the nanostructures synthesized from the vapor process. The application of the Zn2SiO4 straw bundles for the removal of toxic metal ions in water, FeIII and CdII in this case, was investigated and the results indicate that the amount of FeIII and CdII adsorbed onto the surface of the Zn2SiO4 straw bundles increased with the increase of pH values, and the Zn2SiO4 nanostructures showed better removal capacity for FeIII ions than CdII ions.
Co-reporter:Hongtao Huang, Bo Liang, Zhe Liu, Xianfu Wang, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 - vol. 22(Issue 27) pp:NaN13445-13445
Publication Date(Web):2012/05/01
DOI:10.1039/C2JM31679J
Metal oxide nanowires are promising building blocks for thin film transistors due to their one-dimensional geometry in nanoscale, high crystalline nature, and excellent optical and electrical properties. In the past decade, intensive research interest has been drawn to metal oxide nanowire transistors, and various metal oxide nanowires like ZnO, In2O3, and SnO2 have been fabricated into thin film transistors to study their electrical properties and the characteristics as transistor active channels. Much effort has been paid to promote the performance of metal oxide nanowire transistors, and expand the application areas covering from sensing devices, transparent and flexible electronics, to memories and integrated logic circuits. In this review, we highlight the state-of-art progress in metal oxide nanowire transistors, with an emphasis on basic properties and performances. We summarize the characteristics of transistors based on different metal oxide nanowires, the strategies to improve the performance, and various application fields. Finally we present an outlook on the future development of metal oxide nanowire transistors, including the study of material properties, the design of device structures and the development of applications.
Co-reporter:Qiufan Wang, Xianfu Wang, Bin Liu, Gang Yu, Xiaojuan Hou, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2013 - vol. 1(Issue 7) pp:NaN2473-2473
Publication Date(Web):2012/12/18
DOI:10.1039/C2TA01283A
Portable electronic devices which are ultrathin, lightweight and even able to roll-up have attracted much attention. Herein, we report the design of flexible all-solid-state symmetric supercapacitors by using two NiCo2O4 nanowire arrays supported on Ni foams as the electrodes. The as-fabricated symmetric supercapacitors have excellent electrochemical performance with a high cell areal capacitance of 161 mF cm−2 at 1 mA cm−2. Good electrochemical performance stability over 3000 cycles was obtained even when the device was under harsh mechanical conditions including both twisted and bent states. As-fabricated all-solid-state supercapacitors could be charged and power a commercial light-emitting-diode, demonstrating their feasibility as an efficient energy storage component and self-powered micro/nano-system. In addition, we were able to grow NiCo2O4 nanowire arrays on many kinds of flexible substrates, including nickel foam, carbon cloth, Ti foil and polytetrafluoroethylene tape. Our work here opens up opportunities for the device configuration for energy-storage devices in the future wearable electronic area and many other flexible, lightweight and high performance functional nanoscale devices.
Co-reporter:Lijing Wang, Bin Liu, Sihan Ran, Liming Wang, Lina Gao, Fengyu Qu, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2013 - vol. 1(Issue 6) pp:NaN2143-2143
Publication Date(Web):2012/11/30
DOI:10.1039/C2TA00125J
Manganese-based oxides have been proven to be promising materials for applications in high voltage and high energy density Li-ion batteries. In this work, by using hydrothermally synthesized β-MnO2 nanorods as the templates, we prepared single-crystalline CoMn2O4 nano/submicrorods with diameters of about 100 nm and lengths up to tens of micrometers. The electrochemical tests showed that the CoMn2O4 products have a reversible capacity of 512 mA h g−1 at a current density of 200 mA g−1 with a coulombic efficiency of 98% after 100 cycles. A specific capacity of about 400 mA h g−1 was obtained even at a current density as high as 1000 mA g−1, exhibiting a high reversibility and a good capacity retention. This study suggests that CoMn2O4 nano/submicrorods are promising anode materials for high performance lithium-ion batteries.
Co-reporter:Bin Liu, Zhuoran Wang, Yuan Dong, Yuguang Zhu, Yue Gong, Sihan Ran, Zhe Liu, Jing Xu, Zhong Xie, Di Chen and Guozhen Shen
Journal of Materials Chemistry A 2012 - vol. 22(Issue 18) pp:NaN9384-9384
Publication Date(Web):2012/04/02
DOI:10.1039/C2JM16781F
We reported the fabrication of a highly flexible, sensitive, and excellent reproducible photo-detector based on flexible nanoparticle-assembled ZnO cloth, which was synthesized via a carbon cloth templated hydrothermal method. The conductance of the device increased more than 600 times after UV irradiation. The response time and decay time were found to be around 3.2 s and 2.8 s, respectively, indicating fast photoresponse characteristics for the ZnO cloth photodetector. Besides, the free-standing ZnO cloth can be easily thrown into the wastewater solution and used as a high performance recyclable photocatalyst under light irradiation, which can photodegrade organic dyes such as methylene blue (MB) within a short time of 40 min. The ZnO cloth can be used repeatedly without any weight loss. Our work here opens up opportunities for the fabrication of many other flexible, lightweight, foldable, portable and high performance functional devices.
