目的 提高WO3基涂层的气敏性能。方法 以WCl6为前驱体原料，加入一定量的纳米Au颗粒制成稳定的喷涂浆料，采用液相等离子体喷涂技术制备出Au掺杂的WO3基复合涂层。通过扫描电子显微镜（SEM）及其附带的能谱仪、X射线衍射仪（XRD）等对Au-WO3复合涂层的微观结构进行表征。通过自主搭建的气敏性能测试系统对所制备Au-WO3复合涂层的气敏性能进行测试，并探讨了涂层的气敏机理。结果 前驱体液滴在等离子体热源作用下发生溶剂蒸发、WO3形核、结晶和长大等一系列反应，随后形成的WO3固体粒子发生熔化或半熔化，并加速撞击到基体表面形成涂层。在同等条件下，喷涂距离对WO3气敏涂层的结晶度和形貌有很大影响，适宜的喷涂距离（170 mm）下获得的涂层结晶完整且晶粒细小（20~50 nm），有利于涂层气敏性能的发挥。Au-WO3复合涂层的气敏性能均显著优于纯WO3涂层。结论 复合涂层气敏性能的改善归因于涂层中Au和WO3界面处所形成的肖特基结使复合涂层的导电性降低，接触势垒高度增加，初始电阻值变大。

The work aims to improve the gas-sensitivity properties of WO3 based coatings. Au-WO3 composite coating was prepared by plasma spraying technology with mixed feedstock suspensions containing a precursor as WCl6 and a certain ratio of nano-Au. SEM, EDS and XRD were used to characterize the microstructures of Au-WO3 composite coating. The gas-sensitivity properties of prepared Au-WO3 composite coating were studied by a self-made gas-sensitivity test system and the gas sensitivity mechanism was researched. During the suspension plasma spraying, the solvent of the precursor droplets was evaporated and then the nucleation, crystallization and growth of WO3 occurred. Then, the formed WO3 solid particles were melted or semi-melted, and accelerated to impact the surface of the substrate to form a coating. The effects of the spraying distance on the crystallinity and morphology of the WO3 coatings were significant under the same conditions. A coating with integrity crystal and fine grains (20~50 nm) was obtained at the spraying distance of 170 mm which was conductive to gas-sensitivity properties. The gas-sensi?tive properties of the Au-WO3 composite coating were significantly better than that of the pure WO3 coatings. A schottky junction formed at the interface of Au and WO3 improves the gas-sensitive properties of composite coating and leads to a reduction in conductivity of the composite coating. Therefore, the height of the contact barrier increases and initial resistance becomes large.