自组装WO3分级结构制备及其NO2气敏性能增强  

Preparation of Self-Assembled WO Hierarchical Structure and Its Gas Sensing Performance Enhancement to NO

作　　者：丁阳[1] 刘立英[1] 王炳荣 王如志[2] Ding Yang;Liu Liying;Wang Bingrong;Wang Ruzhi(Faculty of Science,Beijing University of Technology,Beijing 100124,China;School of Material Science and Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学理学部,北京100124 [2]北京工业大学材料科学与工程学院,北京100124

出　　处：《微纳电子技术》2020年第9期694-701,734,共9页Micronanoelectronic Technology

基　　金：国家自然科学基金资助项目(11774017)。

摘　　要：采用水热法成功制备了自组装而成的分级WO3纳米结构,并通过改变工艺参数来实现结构与形貌的调控。研究表明,水热酸碱环境对WO3的形貌特征及相结构的影响显著,弱酸性环境下得到的产物是球状的WO3·0.33H2O;而强酸性环境下为块状的WO3·H2O。此外,通过加入适量草酸(H2C2O4),可得到由纳米片自组装而成的WO3分级球状结构。在此基础上,对WO3分级结构的形成机理进行了详细的解释。NO2气敏性能测试发现,自组装而成的球状WO3具有非常优异的气体灵敏度,其灵敏度是块状WO3的6倍多。同时,为了进一步增强自组装球状WO3的气敏性能,对其进行了Au颗粒修饰。修饰后的WO3在工作温度为80℃时,对体积分数1×10^-5 NO2的灵敏度高达1 850,该WO3对NO2的超高灵敏度归因于特殊的自组装结构极大地提升了表面活性位点的数量以及WO3与Au纳米颗粒的催化耦合增强。该研究有望为制备低成本、规模化的高性能NO2气敏材料提供新的技术方案与实现途径。The self-assembled WO3 hierarchical nanostructures were successfully prepared by hydrothermal method,and the structure and morphology could be controlled by adjusting the process parameters.The study results show that the hydrothermal acid-base environment significantly affects the morphology characteristic and phase structure of WO3.In weak acid environment,the product is spherical WO3·0.33 H2O;while in strong acid environment,the product is block WO3·H2O.In addition,by adding appropriate amount of oxalic acid(H2C2O4),the WO3 hierarchical spherical structure formed by self-assembly of nanosheets was obtained.On this basis,the formation mechanism of WO3 hierarchical structure was explained in detail.The NO2 gas sensing performance test shows that the self-assembled spherical WO3 structure has excellent gas sensitivity,which is more than 6 times that of the block WO3.At the same time,the self-assembled spherical WO3 was modified with Au particles to further enhance its gas sensing performance.When the working temperature is 80℃,the sensitivity of the modified WO3 to NO2 with a volume fraction of 1×10^-5 is as high as 1 850.The ultra-high sensitivity of the WO3 to NO2 is due to the special self-assembly structure to greatly increase of the number of surface active sites and the catalytic coupling enhancement between WO3 and Au nanoparticles.The study is expected to provide a new technical scheme and implementation way for the preparation of low cost and large-scale high-performance NO2 gas sensing materials.

关 键 词：水热法 WO3 自组装结构 金修饰 气敏性能 

分 类 号：TB383[一般工业技术—材料科学与工程]