Ag-Modified In₂O₃/ZnO Nanobundles with High Formaldehyde Gas-Sensing Performance.
Ag-modified In2O3/ZnO bundles with micro/nano porous structures have been designed and synthesized with by hydrothermal method continuing with dehydration process. Each bundle consists of nanoparticles, where nanogaps of 10-30 nm are present between the nanoparticles, leading to a porous structure. This porous structure brings high surface area and fast gas diffusion, enhancing the gas sensitivity. Consequently, the HCHO gas-sensing performance of the Ag-modified In2O3/ZnO bundles have been tested, with the formaldehyde-detection limit of 100 ppb (parts per billion) and the response and recover times as short as 6 s and 3 s, respectively, at 300 °C and the detection limit of 100 ppb, response time of 12 s and recover times of 6 s at 100 °C. The HCHO sensing detect limitation matches the health standard limitation on the concentration of formaldehyde for indoor air. Moreover, the strategy to synthesize the nanobundles is just two-step heating and easy to scale up. Therefore, the Ag-modified In2O3/ZnO bundles are ready for industrialization and practical applications.
Beijing National Center for Electron Microscopy, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084, China. ff99@mail.tsinghua.edu.cn.
Fang
F
Fang
National Center for Nanoscience & Technology University of Chinese Academy of Sciences, No. 11 First North Road, Zhongguancun, Beijing 100190, China. whitelu@mail.tsinghua.edu.cn.
Lu
L
Bai
Beijing National Center for Electron Microscopy, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084, China. todongsheng@126.com.
Dongsheng
D
Song
Beijing National Center for Electron Microscopy, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084, China. hpyang1989@163.com.
Hongping
H
Yang
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China. sunxm@mail.buct.edu.cn.
Xiaoming
X
Sun
Beijing National Center for Electron Microscopy, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084, China. hysuny@mail.tsinghua.edu.cn.
Hongyu
H
Sun
Beijing National Center for Electron Microscopy, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084, China. jzhu@mail.tsinghua.edu.cn.
Jing
J
Zhu
D004581:Electronics / Q000295:instrumentation*; D005557:Formaldehyde / Q000032:analysis*; D005740:Gases / Q000032:analysis*; D007204:Indium / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009584:Nitrogen / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D013696:Temperature; D015034:Zinc Oxide / Q000737:chemistry*
D005740:Gases; D007204:Indium; D005557:Formaldehyde; D012834:Silver; C047711:indium oxide; D009584:Nitrogen; D015034:Zinc Oxide
In2O3/ZnO; conductivity; formaldehyde sensing; hierarchical porosity; negative curvature