Investigation of Reduced Graphene Oxide and a Nb-Doped TiO2 Nanotube Hybrid Structure To Improve the Gas-Sensing Response and Selectivity

The precise detection of flammable and explosive gases and vapors remains an important issue because of the increasing demand for renewable energy sources and safety requirements in industrial processes. Metal oxides (TiO2, SnO2, ZnO, etc.) are very attractive materials for the manufacturing of chemical gas sensors. However, their gas selectivity issues and further improvement in the sensing response remain a significant challenge. The incorporation of metal oxides with two-dimensional (2D) graphene oxide (GO) is considered to be a promising approach to obtaining hybrid structures with improved gas-sensing performance. Herein, we report the development of GO and niobium-doped titanium dioxide nanotube (NT) hybrid structures with a tunable selectivity and sensing response against hydrogen gas, achieved by properly controlling the degree of reduction and concentration of GO. The effects of these parameters are systematically studied in terms of the response amplitude and selectivity. It was found that, comp...