Two-step fabrication of ZnO nanosheets for high-performance VOCs gas sensor

Abstract Sheet-like ZnO nanostructure was successfully synthesized through a simple, cost-effective, and low-temperature sonochemical process followed by an etching treatment in an alkali environment at room temperature without any catalyst, template, or seed layer. The morphology and crystallinity of the products were examined by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The as-prepared nanosheets with high purity were single crystals and well-dispersed. A possible formation mechanism of ZnO nanosheets was proposed based on the experimental results. Micro gas sensor fabricated from the as-prepared ZnO nanosheets were tested to different concentration of volatile organic compounds (VOCs) gases. The gas-sensing results revealed that ZnO nanosheets-based micro sensor exhibited high sensitivity to acetaldehyde and formaldehyde with response time within 10 s and the detection limit down to 50 ppb. The excellent sensing property of ZnO nanosheets is mainly attributed to their large specific area, accessible surface, and less agglomerated configuration.

[1]  Andrea Zappettini,et al.  Growth of ZnO tetrapods for nanostructure-based gas sensors , 2010 .

[2]  P. Patil,et al.  Growth of ZnO nanodisk, nanospindles and nanoflowers for gas sensor: pH dependency , 2012 .

[3]  T. Seiyama,et al.  A New Detector for Gaseous Components Using Semiconductive Thin Films. , 1962 .

[4]  L. A. Patil,et al.  Highly sensitive ethanol sensors based on nanocrystalline SnO2 thin films , 2010 .

[5]  Jin Li,et al.  Multilayered ZnO Nanosheets with 3D Porous Architectures: Synthesis and Gas Sensing Application , 2010 .

[6]  Benxia Li,et al.  Hierarchically assembled porous ZnO microstructures and applications in a gas sensor , 2011 .

[7]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[8]  Changsheng Xie,et al.  Formaldehyde sensor based on Ni-doped tetrapod-shaped ZnO nanopowder induced by external magnetic field , 2008 .

[9]  H. Byun,et al.  Controlled Synthesis of ZnO Nanostructures for Sub-ppm-Level VOC Detection , 2012, IEEE Sensors Journal.

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

[11]  J. Zhan,et al.  Fabrication and Gas‐Sensing Properties of Porous ZnO Nanoplates , 2008 .

[12]  Chi-Jung Chang,et al.  Selective growth of ZnO nanorods for gas sensors using ink-jet printing and hydrothermal processes , 2010 .

[13]  Claes-Göran Granqvist,et al.  Nanomaterials for environmental applications: Novel WO3-based gas sensors made by advanced gas deposition , 2004 .

[14]  H. Shiku,et al.  A facile method for patterned growth of ZnO nanowires using a black ink , 2012, Electronic Materials Letters.

[15]  H. Lee,et al.  Temperature dependence of the growth of ZnO nanorod arrays by electrochemical deposition , 2011 .

[16]  Su-Jae Lee,et al.  Fabrication and Characterization of ZnO Nanofibers by Electrospinning , 2009 .

[17]  Haiqiang Lu,et al.  Facile synthesis and ultrahigh ethanol response of hierarchically porous ZnO nanosheets , 2012 .

[18]  Chengrong Li,et al.  Triethylamine gas sensor based on ZnO nanorods prepared by a simple solution route , 2009 .

[19]  Tao Luo,et al.  Novel porous single-crystalline ZnO nanosheets fabricated by annealing ZnS(en)0.5 (en = ethylenediamine) precursor. Application in a gas sensor for indoor air contaminant detection , 2009, Nanotechnology.

[20]  Sten-Eric Lindquist,et al.  Three-dimensional array of highly oriented crystalline ZnO microtubes , 2001 .

[21]  Jinchai Li,et al.  Controlled synthesis of ZnO hollow microspheres via precursor-template method and its gas sensing property , 2012 .

[22]  Chunrong Jia,et al.  VOCs in industrial, urban and suburban neighborhoods, Part 1: Indoor and outdoor concentrations, variation, and risk drivers , 2008 .

[23]  Jeong-Ok Lim,et al.  Selective Growth of ZnO Nanorods and Its Gas Sensor Application , 2012, IEEE Sensors Journal.

[24]  Peng Sun,et al.  Dispersive SnO2 nanosheets: Hydrothermal synthesis and gas-sensing properties , 2011 .

[25]  P. Hesketh,et al.  Synthesis and gas sensing properties of ZnO single crystal flakes , 2005 .

[26]  Andrew G. Glen,et al.  APPL , 2001 .

[27]  S. Phanichphant,et al.  Doctor-bladed thick films of flame-made Pd/ZnO nanoparticles for ethanol sensing , 2008 .