A facile one-step hydrothermal synthesis of NiO/ZnO heterojunction microflowers for the enhanced formaldehyde sensing properties

Abstract NiO/ZnO heterojunction microflowers were successfully synthesized by using a facile one-step hydrothermal process followed by calcination. The structural features were mainly characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It is found that the obtained products showed flower-like structures assembled by a number of ZnO porous nanosheets, and which were successfully retained after introducing NiO. The formaldehyde gas sensing properties were systematically investigated between the pure and NiO/ZnO microflowers. NiO/ZnO microflower sensor exhibited the enhanced response and lower operating temperature compared to pure one. Especially, the 3 mol% NiO/ZnO microflower sensor exhibited the highest responses compared with others at a relatively lower operating temperature of 200 °C. In addition, fast response and recovery, good reproducibility and stability, and good selectivity to formaldehyde were also obtained, indicating the formation of NiO/ZnO heterojunction in favor of improving the sensing properties. Meanwhile, the sensing enhancement mechanism of the NiO/ZnO microflowers was also discussed, which is related to the formation of hetrojunction at interface and the high catalytic activity of NiO.

[1]  Giuliano Martinelli,et al.  Moisture effects on pure and Pd-doped SnO2 thick films analysed by FTIR spectroscopy and conductance measurements , 1995 .

[2]  Lichun Zhang,et al.  Enclosed hollow tubular ZnO: Controllable synthesis and their high performance cataluminescence gas sensing of H2S , 2017 .

[3]  Kengo Shimanoe,et al.  Contribution of electron tunneling transport in semiconductor gas sensor , 2007 .

[4]  R. P. Pant,et al.  Effect of Ni doping on thick film SnO2 gas sensor , 2006 .

[5]  Peng Sun,et al.  One-pot synthesis of hierarchical WO3 hollow nanospheres and their gas sensing properties , 2015 .

[6]  Chao Li,et al.  Electrospun nanofibers of p-type NiO/n-type ZnO heterojunction with different NiO content and its influence on trimethylamine sensing properties , 2015 .

[7]  Il-Doo Kim,et al.  Thin-walled NiO tubes functionalized with catalytic Pt for highly selective C2H5OH sensors using electrospun fibers as a sacrificial template. , 2011, Chemical communications.

[8]  Seong H. Kim,et al.  Fabrication of Nb-doped ZnO nanowall structure by RF magnetron sputter for enhanced gas-sensing properties , 2017 .

[9]  P. K. Basu,et al.  Nanocrystalline Metal Oxides for Methane Sensors: Role of Noble Metals , 2009, J. Sensors.

[10]  S. Hussain,et al.  Embedded ZnO nanorods and gas-sensing properties , 2015 .

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

[12]  Zhihua Wang,et al.  Effects of rare earth element doping on the ethanol gas-sensing performance of three-dimensionally ordered macroporous In2O3 , 2016 .

[13]  Lili Wang,et al.  Fast response/recovery performance of comb-like Co3O4 nanostructure , 2014 .

[14]  Chia-Yen Lee,et al.  Formaldehyde Gas Sensors: A Review , 2013, Sensors.

[15]  D. Meng,et al.  Flower-like NiO hierarchical microspheres self-assembled with nanosheets: Surfactant-free solvothermal synthesis and their gas sensing properties , 2015 .

[16]  Seung Hwan Ko,et al.  Nanoforest of hydrothermally grown hierarchical ZnO nanowires for a high efficiency dye-sensitized solar cell. , 2011, Nano letters.

[17]  Zheng Xu,et al.  Photochemical deposition of Ag nanocrystals on hierarchical ZnO microspheres and their enhanced gas-sensing properties , 2012 .

[18]  Hongbing Lu,et al.  Synthesis of porous NiO-In2O3 composite nanofibers by electrospinning and their highly enhanced gas sensing properties , 2017 .

[19]  Jian Song,et al.  NiO@ZnO heterostructured nanotubes: coelectrospinning fabrication, characterization, and highly enhanced gas sensing properties. , 2012, Inorganic chemistry.

[20]  Xinxin Xing,et al.  Highly sensitive formaldehyde gas sensor based on hierarchically porous Ag-loaded ZnO heterojunction nanocomposites , 2017 .

[21]  Zhe Zhao,et al.  A CuO–ZnO nanostructured p–n junction sensor for enhanced N-butanol detection , 2016 .

[22]  M. Abdel-Rahim,et al.  CuO nanoparticles synthesized by microwave-assisted method for methane sensing , 2016 .

[23]  Changsheng Xie,et al.  Fabrication and formaldehyde gas-sensing property of ZnO–MnO2 coplanar gas sensor arrays , 2010 .

[24]  S. G. Kumar,et al.  Zinc oxide based photocatalysis: tailoring surface-bulk structure and related interfacial charge carrier dynamics for better environmental applications , 2015 .

[25]  Weiwei Guo,et al.  Hydrothermal synthesis and gas-sensing properties of ultrathin hexagonal ZnO nanosheets , 2014 .

[26]  Cumali Sabah,et al.  Metal mesh filters based on Ti, ITO and Cu thin films for terahertz waves , 2016 .

[27]  Li-ping Zhu,et al.  Valence-band offset of p-NiO/n-ZnO heterojunction measured by X-ray photoelectron spectroscopy , 2011 .

[28]  U. Hashim,et al.  A simple preparation of ZnO nanocones and exposure to formaldehyde , 2014 .

[29]  Ghenadii Korotcenkov,et al.  Metal oxide composites in conductometric gas sensors: Achievements and challenges , 2017 .

[30]  I. Djerdj,et al.  Porous NiO nanosheets self-grown on alumina tube using a novel flash synthesis and their gas sensing properties , 2015 .

[31]  S. R. Silva,et al.  From 1D and 2D ZnO nanostructures to 3D hierarchical structures with enhanced gas sensing properties. , 2014, Nanoscale.

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

[33]  Xianying Wang,et al.  Enhanced formaldehyde sensing properties of hollow SnO2 nanofibers by graphene oxide , 2017 .

[34]  Fanli Meng,et al.  Assembly of 3D flower-like NiO hierarchical architectures by 2D nanosheets: Synthesis and their sensing properties to formaldehyde , 2017 .

[35]  Zhihao Yuan,et al.  From function-guided assembly of a lotus leaf-like ZnO nanostructure to a formaldehyde gas-sensing application , 2013 .

[36]  Y. Tong,et al.  Amorphous NiO electrocatalyst overcoated ZnO nanorod photoanodes for enhanced photoelectrochemical performance , 2016 .

[37]  X. Duan,et al.  Electroluminescence and Photocurrent Generation from Atomically Sharp WSe2/MoS2 Heterojunction p–n Diodes , 2014, Nano letters.

[38]  Huanli Dong,et al.  Recent advances in one-dimensional organic p–n heterojunctions for optoelectronic device applications , 2016 .

[39]  Jing Cao,et al.  Controllable synthesis of zinc oxide hierarchical architectures and their excellent formaldehyde gas sensing performances , 2017 .

[40]  Hui Li,et al.  High sensitive and selective formaldehyde sensors based on nanoparticle-assembled ZnO micro-octahedrons synthesized by homogeneous precipitation method , 2011 .

[41]  Giovanni Neri,et al.  Detection of hazardous volatile organic compounds (VOCs) by metal oxide nanostructures-based gas sensors: A review , 2016 .

[42]  Xu Liu,et al.  Nonaqueous synthesis of Ag-functionalized In2O3/ZnO nanocomposites for highly sensitive formaldehyde sensor , 2016 .

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

[44]  C. Xie,et al.  Enhanced gas sensing performance of Li-doped ZnO nanoparticle film by the synergistic effect of oxygen interstitials and oxygen vacancies , 2015 .

[45]  Magnus Willander,et al.  UV photo-detector based on p-NiO thin film/n-ZnO nanorods heterojunction prepared by a simple process , 2015 .

[46]  Zhi-xuan Cheng,et al.  Novel lotus root slice-like self-assembled In2O3 microspheres: Synthesis and NO2-sensing properties , 2013 .

[47]  J. Zhan,et al.  Facile synthesis and high formaldehyde-sensing performance of NiO–SnO2 hybrid nanospheres , 2016 .

[48]  Li Li,et al.  Shuttle-like ZnO nano/microrods: Facile synthesis, optical characterization and high formaldehyde sensing properties , 2011 .

[49]  Changsheng Xie,et al.  Metal-oxide-semiconductor based gas sensors: screening, preparation, and integration. , 2017, Physical chemistry chemical physics : PCCP.

[50]  N. Yamazoe,et al.  Oxide Semiconductor Gas Sensors , 2003 .

[51]  J. Shim,et al.  Controlled synthesis of porous Ni-doped SnO2 microstructures and their enhanced gas sensing properties , 2017 .

[52]  D. Kohl.  The role of noble metals in the chemistry of solid-state gas sensors , 1990 .

[53]  Peng Sun,et al.  Acetone gas sensor based on NiO/ZnO hollow spheres: Fast response and recovery, and low (ppb) detection limit. , 2017, Journal of colloid and interface science.

[54]  Zheng Lou,et al.  Controllable and enhanced HCHO sensing performances of different-shelled ZnO hollow microspheres , 2013 .

[55]  Peng Sun,et al.  Facile synthesis and gas sensing properties of the flower-like NiO-decorated ZnO microstructures , 2016 .

[56]  Bingqiang Cao,et al.  Near room-temperature triethylamine sensor constructed with CuO/ZnO P-N heterostructural nanorods directly on flat electrode , 2016 .