Abstract WO3-SnO2 nanosheet (NS) composites consisting of inner WO3 nanosheets surrounded by outer mixed phase SnO2 nanoparticles (NPs) were successfully synthesized by a simple two-step hydrothermal method. The density of SnO2 NPs on WO3 NSs can be controlled from sparse discrete state to complete shell structure by varying the amount of tin precursor. Apparent interface state density dependent gas sensing responses were observed for the WO3-SnO2 nanocomposites. The response of the WO3-SnO2 nanocomposites coated with complete SnO2 shell to 50 ppm acetone vapor is as high as 32.1, ∼10 times higher than that of the pristine WO3 NS sensor, with a response time less than 2 s. The improvement in response and selectivity of the WO3-SnO2 nanocomposite sensors upon exposure to acetone molecules can be mainly attributed to the multifunctional interfaces between WO3 NSs and SnO2 NPs, exposed special facets of WO3 NSs, core-shell type nanostructures as well as the special physical and chemical properties of acetone molecules.

中文翻译：

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WO 3 -SnO 2 纳米片复合材料：水热合成和气敏机理

摘要 通过简单的两步水热法成功合成了由内部 WO3 纳米片和外部混合相 SnO2 纳米颗粒 (NPs) 包围的 WO3-SnO2 纳米片 (NS) 复合材料。通过改变锡​​前驱体的量，可以控制 WO3 NSs 上 SnO2 NPs 的密度从稀疏离散状态到完整的壳结构。对于 WO3-SnO2 纳米复合材料，观察到明显的界面态密度依赖的气体传感响应。涂覆有完整 SnO2 壳的 WO3-SnO2 纳米复合材料对 50 ppm 丙酮蒸汽的响应高达 32.1，是原始 WO3 NS 传感器的 10 倍，响应时间小于 2 秒。