文献类型：期刊文献

英文题名：From the Surface Reaction Control to Gas-Diffusion Control: The Synthesis of Hierarchical Porous SnO2 Microspheres and Their Gas-Sensing Mechanism

作者：Wang, Xiaobing[1];Wang, Yuanyuan[1];Tian, Fei[1];Liang, Huijun[1,3];Wang, Kui[1];Zhao, Xiaohua[1];Lu, Zhansheng[2];Jiang, Kai[1];Yang, Lin[1];Lou, Xiangdong[1]

第一作者：Wang, Xiaobing

通讯作者：Yang, L[1]

机构：[1]Henan Normal Univ, Minist Educ, Collaborat Innovat Ctr Henan Prov Green Mfg Fine, Key Lab Green Chem Media & React,Sch Chem & Chem, Xinxiang 453007, Henan, Peoples R China;[2]Henan Normal Univ, Coll Phys & Informat Engn, Xinxiang 453007, Henan, Peoples R China;[3]Xinxiang Univ, Coll Chem & Chem Engn, Xinxiang 453003, Peoples R China

第一机构：Henan Normal Univ, Minist Educ, Collaborat Innovat Ctr Henan Prov Green Mfg Fine, Key Lab Green Chem Media & React,Sch Chem & Chem, Xinxiang 453007, Henan, Peoples R China

通讯机构：[1]corresponding author), Henan Normal Univ, Minist Educ, Collaborat Innovat Ctr Henan Prov Green Mfg Fine, Key Lab Green Chem Media & React,Sch Chem & Chem, Xinxiang 453007, Henan, Peoples R China.

年份：2015

卷号：119

期号：28

起止页码：15963-15976

外文期刊名：JOURNAL OF PHYSICAL CHEMISTRY C

收录：;EI(收录号：20152901040258);Scopus(收录号：2-s2.0-84937147604);WOS:【SCI-EXPANDED(收录号:WOS:000358337700023)】；

基金：This work was supported by the Program for Chang Jiang Scholars and Innovative Research Team in University (Grant No. IRT 1061), the National Natural Science Foundation of China (No.11147006), and Henan Normal University Innovation Funds for Postgraduate (No.YL201202).

语种：英文

外文关键词：Chemical detection - Chemical sensors - Diffusion in gases - Gas detectors - Gases - Microspheres - Pore size - Rate constants - Sintering - Specific surface area - Thick films

摘要：A series of hierarchical porous SnO2 microspheres (SnO2-Ms) with same sizes of nanoparticles were fabricated through increasing the reaction time of the one-step hydrothermal method. Especially, these SnO2-Ms also have the different specific surface areas and pores sizes. When they are applied in sintering type thick film gas sensors, through comparing the gas-sensing property of the as-prepared SnO2-Ms, it can clearly demonstrate that the surface chemical reaction (SCR) control of the sensing properties of sensors is gradually replaced by gas diffusion control with the increasing operation temperature (To). For the first time, this dual control is discovered through contrast experiments. According to the testing results, the sensing mechanism of sensors can be explained by many factors, such as the reaction rate constant of the SCR, the Knudsen diffusion coefficient of the target gas, the T-o, the specific surface area, the pore size, and the change of the H2O, etc. A pore canal model and a hollow sphere model are introduced, which can effectively explain the sensing mechanism of gas sensors. This discovery can make up for the inadequacy of the surface-control and the diffusion-control theory, and expound their interrelationship. This discovery also provides a novel strategy for studying the sensing mechanism of sensors, which is expected to open up exciting opportunities for improving the sensing properties of the gas-sensing materials and studying some gas solid catalytic phenomena.