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

• •A simple and universal method for the preparation of metal oxide nanotube arrays was provided. • •The WO 3 nanotube arrays exhibit superior gas sensing performance. • •Discussed the formation mechanism of nanotubes induced by WO 3 thin film seeds. Tungsten oxide (WO 3 ) has a great significance in variety of fields. In this work, WO 3 nanotube arrays (NTs) were successfully fabricated onto a Si substrate covered with WO 3 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 WO 3 thin film seeds was detailed discussed. Furthermore, the H 2 S 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.