Role of the heterojunctions in In2O3-composite SnO2 nanorod sensors and their remarkable gas-sensing performance for NO(x) at room temperature.

Establishing heterostructures, as a good strategy to improve gas sensing performance, has been studied extensively. In this research, In2O3-composite SnO2 nanorod (ICTOs) heterostructures have been prepared via electrospinning, followed by calcination. It is found that In2O3 can improve the carrier density and oxygen deficiency of SnO2. In particular, the 3ICTO (Sn : In atom ratio of 25 : 0.3) nanorods with special particle distributions show an excellent sensing response towards different concentrations of NOx at room temperature. The highest sensing response is up to 8.98 for 100 ppm NOx with a fast response time of 4.67 s, which is over 11 times higher than that of pristine SnO2 nanorods at room temperature and the lowest detection limit is down to 0.1 ppm. More significantly, it presents good stability after 30 days for NOx of low concentration (0.1 ppm and 0.5 ppm). In addition, the rational band structure model combined with the surface depletion model which describe the NOx gas sensing mechanism of 3ICTO are presented. The 3ICTO nanorods may be promising in the application of gas sensors.

[1]  Dongxiang Zhou,et al.  Nanocrystalline In2O3–SnO2 thick films for low-temperature hydrogen sulfide detection , 2011 .

[2]  M. Amati,et al.  Micro- and Nanopyramids of Manganese-Doped Indium Oxide , 2010 .

[3]  Luca Francioso,et al.  NO2-gas-sensing properties of mixed In2O3–SnO2 thin films , 2005 .

[4]  N. Shaalan,et al.  Effect of micro-electrode geometry on NO2 gas-sensing characteristics of one-dimensional tin dioxide nanostructure microsensors , 2011 .

[5]  Y. Bando,et al.  Oxygen Vacancy Driven Modulations in In2O3 Pyramidal Beaded Nanowires , 2012 .

[6]  Y. Kang,et al.  One-pot facile synthesis of Janus-structured SnO2-CuO composite nanorods and their application as anode materials in Li-ion batteries. , 2013, Nanoscale.

[7]  Da-Hai Xia,et al.  Corrosion behavior of tinplate in NaCl solution , 2012 .

[8]  Zhongchang Wang,et al.  Enhanced gas sensing properties by SnO2 nanosphere functionalized TiO2 nanobelts , 2012 .

[9]  A. Maiti,et al.  SnO2 nanoslab as NO2 sensor: identification of the NO2 sensing mechanism on a SnO2 surface. , 2014, ACS applied materials & interfaces.

[10]  Wei Zhou,et al.  Highly dispersed Ni-decorated porous hollow carbon nanofibers: fabrication, characterization, and NOx gas sensors at room temperature , 2012 .

[11]  Electrical Characterization of Carbon Monoxide Sensitive High Temperature Sensor Diode Based on Catalytic Metal Gate—Insulator—Silicon , 2002 .

[12]  Jinwoo Lee,et al.  Ordered mesoporous Zn-doped SnO2 synthesized by exotemplating for efficient dye-sensitized solar cells , 2011 .

[13]  Michele Penza,et al.  NOX GAS SENSING CHARACTERISTICS OF WO3 THIN FILMS ACTIVATED BY NOBLE METALS (PD, PT, AU) LAYERS , 1998 .

[14]  Mohammad Mansoob Khan,et al.  Highly photoactive SnO2 nanostructures engineered by electrochemically active biofilm , 2014 .

[15]  Jiming Hao,et al.  Complete combustion of methane over indium tin oxides catalysts. , 2006, Environmental science & technology.

[16]  Y. Bando,et al.  Enhanced Field Emission Performance of Ga-Doped In2O3(ZnO)3 Superlattice Nanobelts , 2011 .

[17]  Chan Woong Na,et al.  Selective detection of NO2 and C2H5OH using a Co3O4-decorated ZnO nanowire network sensor. , 2011, Chemical communications.

[18]  Yi Xie,et al.  Ultrathin two-dimensional MnO2/graphene hybrid nanostructures for high-performance, flexible planar supercapacitors. , 2013, Nano letters.

[19]  Weiguo Song,et al.  Low-cost synthesis of graphitic carbon nanofibers as excellent room temperature sensors for explosive gases , 2012 .

[20]  D. Dzombak,et al.  Electrochemical Impedance Spectroscopy (EIS) Based Characterization of Mineral Deposition from Precipitation Reactions , 2012 .

[21]  M. Rahman,et al.  CuO codoped ZnO based nanostructured materials for sensitive chemical sensor applications. , 2011, ACS applied materials & interfaces.

[22]  Ooi Kiang Tan,et al.  Low‐Temperature Growth of SnO2 Nanorod Arrays and Tunable n–p–n Sensing Response of a ZnO/SnO2 Heterojunction for Exclusive Hydrogen Sensors , 2011 .

[23]  Monika Tomar,et al.  Enhanced response characteristics of SnO2 thin film based NO2 gas sensor integrated with nanoscaled metal oxide clusters , 2013 .

[24]  Partha Pratim Ray,et al.  Synthesis of ZnO composited TiO2 nanoparticle and its application in dye sensitized solar cells: A novel approach in enhancing open-circuit voltage , 2014 .

[25]  J. Glass,et al.  Solution-processed, antimony-doped tin oxide colloid films enable high-performance TiO2 photoanodes for water splitting. , 2013, Nano letters.

[26]  J. Sambrano,et al.  Preparation of TiO2/SnO2 thin films by sol-gel method and periodic B3LYP simulations. , 2014, The journal of physical chemistry. A.

[27]  Tong Zhang,et al.  High performance room temperature NO2 sensors based on reduced graphene oxide-multiwalled carbon nanotubes-tin oxide nanoparticles hybrids , 2015 .

[28]  Jisheng Pan,et al.  Annealing temperature dependent oxygen vacancy behavior in SnO2 thin films fabricated by pulsed laser deposition , 2011 .

[29]  T. V. Belysheva,et al.  Conductivity of SnO2-In2O3 nanocrystalline composite films , 2010 .

[30]  Meihong Fan,et al.  Trimethylamine sensors with enhanced anti-humidity ability fabricated from La0.7Sr0.3FeO3 coated In2O3-SnO2 composite nanofibers , 2014 .

[31]  Li Zhang,et al.  Electrospun Nanofibers of ZnO−SnO2 Heterojunction with High Photocatalytic Activity , 2010 .

[32]  Xuejuan Wan,et al.  Gas sensing properties of Cu2O and its particle size and morphology-dependent gas-detection sensitivity , 2014 .

[33]  Sunghoon Park,et al.  UV-enhanced NO2 gas sensing properties of SnO2-core/ZnO-shell nanowires at room temperature. , 2013, ACS applied materials & interfaces.

[34]  Jing-Chie Lin,et al.  Fabrication of a novel microsensor consisting of electrodeposited ZnO nanorod-coated crossed Cu micropillars and the effects of nanorod coating morphology on the gas sensing. , 2014, ACS applied materials & interfaces.

[35]  Hyunsung Ko,et al.  Synthesis of nanograined ZnO nanowires and their enhanced gas sensing properties. , 2012, ACS applied materials & interfaces.

[36]  V. Mastelaro,et al.  Surface morphology-dependent room-temperature LaFeO₃ nanostructure thin films as selective NO₂ gas sensor prepared by radio frequency magnetron sputtering. , 2014, ACS applied materials & interfaces.

[37]  Kijung Yong,et al.  CuO/ZnO Heterostructured Nanorods: Photochemical Synthesis and the Mechanism of H2S Gas Sensing , 2012 .

[38]  Weiqi Wang,et al.  Synergic effect within n-type inorganic–p-type organic nano-hybrids in gas sensors , 2013 .

[39]  Huan Yu,et al.  Nickel(II) dithiocarbamate complexes containing sulforhodamine B as fluorescent probes for selective detection of nitrogen dioxide. , 2013, Journal of the American Chemical Society.

[40]  C. Liu,et al.  Low-temperature hydrothermal synthesis of WO3 nanorods and their sensing properties for NO2 , 2012 .

[41]  Qingjie Zhang,et al.  Synthesis, Characterization, and Photocatalytic Activity of Zn-Doped SnO2 Hierarchical Architectures Assembled by Nanocones , 2009 .

[42]  Jordi Arbiol,et al.  In2O3 films deposited by spray pyrolysis as a material for ozone gas sensors , 2004 .

[43]  He Tian,et al.  Novel Field-Effect Schottky Barrier Transistors Based on Graphene-MoS2 Heterojunctions , 2014, Scientific Reports.

[44]  Zhibin Yu,et al.  Vertically aligned tungsten oxide nanorod film with enhanced performance in photoluminescence humidity sensing , 2014 .

[45]  Z. Alferov,et al.  The double heterostructure: the concept and its applications in physics, electronics, and technology (Nobel lecture). , 2001, Chemphyschem : a European journal of chemical physics and physical chemistry.

[46]  Junhong Chen,et al.  Indium-doped SnO2 nanoparticle–graphene nanohybrids: simple one-pot synthesis and their selective detection of NO2 , 2013 .

[47]  Giorgio Sberveglieri,et al.  Novel Synthesis and Gas Sensing Performances of CuO–TiO2 Nanocomposites Functionalized with Au Nanoparticles , 2011 .

[48]  G. Lu,et al.  Novel Zn-doped SnO2 hierarchical architectures: synthesis, characterization, and gas sensing properties , 2012 .

[49]  Fang‐Xing Xiao.  Construction of highly ordered ZnO-TiO2 nanotube arrays (ZnO/TNTs) heterostructure for photocatalytic application. , 2012, ACS applied materials & interfaces.

[50]  K. Shi,et al.  Facile synthesis of CaO–SnO2 nanocrystalline composite rods by electrospinning method with enhanced gas sensitive performance at room temperature , 2013 .

[51]  J. Ying,et al.  SnO2−In2O3 Nanocomposites as Semiconductor Gas Sensors for CO and NOx Detection , 2007 .

[52]  Derek R. Miller,et al.  Nanoscale metal oxide-based heterojunctions for gas sensing: A review , 2014 .

[53]  Monika Tomar,et al.  Low temperature operating SnO2 thin film sensor loaded with WO3 micro-discs with enhanced response for NO2 gas , 2012 .

[54]  Guozhi Zhang,et al.  Electrospun In2O3/α-Fe2O3 heterostructure nanotubes for highly sensitive gas sensor applications , 2013 .

[55]  Haihui Wang,et al.  High specific capacity of TiO2-graphene nanocomposite as an anode material for lithium-ion batteries in an enlarged potential window , 2012 .

[56]  Ke‐long Huang,et al.  Kinetic study on Li2.8(V0.9Ge0.1)2(PO4)3 by EIS measurement , 2008 .

[57]  Mei Chen,et al.  Porous ZnO Polygonal Nanoflakes: Synthesis, Use in High-Sensitivity NO2 Gas Sensor, and Proposed Mechanism of Gas Sensing , 2011 .

[58]  Edvige Celasco,et al.  Optimization of 1D ZnO@TiO2 core-shell nanostructures for enhanced photoelectrochemical water splitting under solar light illumination. , 2014, ACS applied materials & interfaces.

[59]  Kazuhiro Takanabe,et al.  Synthesis of a carbon nitride structure for visible-light catalysis by copolymerization. , 2010, Angewandte Chemie.

[60]  Mordechay Schlesinger,et al.  Modern Aspects of Electrochemistry, Number 43 , 2009 .

[61]  Wei Zhou,et al.  Alumina decorated TiO2 nanotubes with ordered mesoporous walls as high sensitivity NO(x) gas sensors at room temperature. , 2013, Nanoscale.

[62]  In-Sung Hwang,et al.  Highly conductive coaxial SnO(2)-In(2)O(3) heterostructured nanowires for Li ion battery electrodes. , 2007, Nano letters.

[63]  Kewei Zhang,et al.  Synthesis mechanism and gas-sensing application of nanosheet-assembled tungsten oxide microspheres , 2014 .

[64]  Bipin Kumar Gupta,et al.  Probing the highly efficient room temperature ammonia gas sensing properties of a luminescent ZnO nanowire array prepared via an AAO-assisted template route. , 2014, Dalton transactions.

[65]  H. Fan,et al.  In2O3/SnO2 heterojunction microstructures: Facile room temperature solid-state synthesis and enhanced Cl2 sensing performance , 2013 .

[66]  A. Gurlo,et al.  Nanosensors: towards morphological control of gas sensing activity. SnO2, In2O3, ZnO and WO3 case studies. , 2011, Nanoscale.

[67]  J. Hao,et al.  Selective catalytic reduction of NOx with propene over SnO2/Al2O3 catalyst , 2010 .

[68]  Xiaobo Zhang,et al.  Excellent toluene sensing properties of SnO2-Fe2O3 interconnected nanotubes. , 2013, ACS applied materials & interfaces.

[69]  Bo Dong,et al.  A Rapidly Responding Sensor for Methanol Based on Electrospun In2O3–SnO2 Nanofibers , 2010 .

[70]  Y. Im,et al.  Synthesis of Vertically Conformal ZnO/CuO Core–Shell Nanowire Arrays by Electrophoresis-Assisted Electroless Deposition , 2014 .