Enhanced room-temperature NO2 gas sensing with TeO2/SnO2 brush- and bead-like nanowire hybrid structures

We have synthesized two highly sensitive, room-temperature operating TeO2/SnO2 gas sensors with hierarchical nanowire structures. One is a brush-like nanostructure, from a two-step thermal vapor-transport route, and the other one is a TeO2/SnO2 bead-like nanostructure, from annealing of the former. The TeO2/SnO2 nanostructures exhibit a greatly enhanced room-temperature gas-sensing response compared to pristine TeO2 nanowires in the sequence: TeO2/SnO2 bead-like structure > brush-like structure > pristine TeO2 nanowire. The response of the TeO2/SnO2 bead-like structure is in a range of 10 to 20 against NO2 gas of ppm levels (3-100 ppm) at room temperature. This compares favorably to the response, smaller than 2, for the pristine TeO2 nanowires. Interestingly, the TeO2/SnO2 bead-like structure exhibits a typical n-type gas-sensing behavior, in contrast to the p-type behavior from the brush-like and the pristine TeO2 structures. Possible hybrid growth and sensing mechanisms are discussed.

[1]  J. H. Lee,et al.  Gas sensors using hierarchical and hollow oxide nanostructures: Overview , 2009 .

[2]  Vinay Gupta,et al.  A low temperature operated NO2 gas sensor based on TeO2/SnO2 p–n heterointerface , 2013 .

[3]  Ho Won Jang,et al.  One-Dimensional Oxide Nanostructures as Gas-Sensing Materials: Review and Issues , 2010, Sensors.

[4]  Nguyen Van Hieu,et al.  Comparative study of gas sensor performance of SnO2 nanowires and their hierarchical nanostructures , 2010 .

[5]  Dong Xiang,et al.  Metal Oxide Gas Sensors: Sensitivity and Influencing Factors , 2010, Sensors.

[6]  Nguyen Duc Hoa,et al.  Design of SnO2/ZnO hierarchical nanostructures for enhanced ethanol gas-sensing performance , 2012 .

[7]  Enhanced Gas Sensing Properties of Pt-Loaded TeO 2 Nanorods , 2012 .

[8]  T. Merle-Méjean,et al.  Crystal structure, Raman spectrum and lattice dynamics of a new metastable form of tellurium dioxide: γ-TeO2 , 2000 .

[9]  Monika Tomar,et al.  Room temperature trace level detection of NO2 gas using SnO2 modified carbon nanotubes based sensor , 2012 .

[10]  Xinyu Xue,et al.  Synthesis and H2S Sensing Properties of CuO-SnO2Core/Shell PN-Junction Nanorods , 2008 .

[11]  M. Cao,et al.  Synthesis and enhanced ethanol sensing properties of α-Fe2O3/ZnO heteronanostructures , 2009 .

[12]  A. Tepore,et al.  Porous tellurium oxide microtubes for room-temperature NO2 gas sensors , 2014 .

[13]  Yung-Chiun Her,et al.  Vapor-solid growth of p-Te/n-SnO2 hierarchical heterostructures and their enhanced room-temperature gas sensing properties. , 2014, ACS applied materials & interfaces.

[14]  Murthy Chavali,et al.  Effect of ‘Pt’ loading in ZnO–CuO hetero-junction material sensing carbon monoxide at room temperature , 2011 .

[15]  Zhifu Liu,et al.  Room temperature gas sensing of p-type TeO2 nanowires , 2007 .

[16]  D. Kang,et al.  Ultrasensitive single crystalline TeO2 nanowire based hydrogen gas sensors , 2014 .

[17]  Yanbai Shen,et al.  A low-temperature n-propanol gas sensor based on TeO2 nanowires as the sensing layer , 2015 .

[18]  Wei Lu,et al.  Branched SnO2 nanowires on metallic nanowire backbones for ethanol sensors application , 2008 .

[19]  Russell Binions,et al.  Metal Oxide Semi-Conductor Gas Sensors in Environmental Monitoring , 2010, Sensors.

[20]  B. Song,et al.  Secondary Facet-Selective Nucleation and Growth: Highly Oriented Straight SnO2 Nanowire Arrays on Primary Microrods , 2009 .

[21]  Emanuela Filippo,et al.  Transition from n- to p-type electrical conductivity induced by ethanol adsorption on α-tellurium dioxide nanowires , 2009 .

[22]  Zhifu Liu,et al.  Synthesis and Characterization of TeO2 Nanowires , 2008 .

[23]  Yuan Zhang,et al.  Brush-Like Hierarchical ZnO Nanostructures: Synthesis, Photoluminescence and Gas Sensor Properties , 2009 .

[24]  Marc Kastner,et al.  Bonding Bands, Lone-Pair Bands, and Impurity States in Chalcogenide Semiconductors , 1972 .

[25]  Young-Jin Choi,et al.  Novel fabrication of an SnO2 nanowire gas sensor with high sensitivity , 2008, Nanotechnology.

[26]  Kyung Soo Park,et al.  On-chip fabrication of ZnO-nanowire gas sensor with high gas sensitivity , 2009 .

[27]  M. Smirnov,et al.  Vibrational and structural properties of glass and crystalline phases of TeO2 , 2003 .

[28]  Hyoun-woo Kim,et al.  Simply heating to remove the sacrificial core TeO2 nanowires and to generate tubular nanostructures of metal oxides , 2011 .

[29]  Ma Shuangyun,et al.  Enhanced response characteristics of p-porous silicon (substrate)/p-TeO2 (nanowires) sensor for NO2 detection , 2014 .

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

[31]  Daihua Zhang,et al.  In2O3 nanowires as chemical sensors , 2003 .