In situ growth of WO3 nanotube arrays and their H2S gas sensing properties for reduced operating temperature

Abstract Tungsten oxide (WO3) has a great significance in variety of fields. In this work, WO3 nanotube arrays (NTs) were successfully fabricated onto a Si substrate covered with WO3 thin film by thermal evaporation method. Various characterization indicated that these NTs show a hexagonal shape at their tips and the side planes are well-faceted. The formation mechanism of NTs induced by WO3 thin film seeds was detailed discussed. Furthermore, the H2S sensing performance was analyzed and exhibited good performance at low temperature, which is beneficial to saving power and integrated device. Therefore, this study provides a simple and universal method for the preparation of metal oxide nanotube arrays, which provides a useful platform for the high-performance gas sensors.