Enhanced gas sensing properties by SnO2 nanosphere functionalized TiO2 nanobelts

We report synthesis of hierarchical nanostructures of SnO2 nanosphere functionalized TiO2 nanobelts as a novel sensing material by a simple hydrothermal technique. A systematic comparison study reveals an enhanced gas sensing performance for the sensor made of SnO2 and TiO2 toward volatile organic compounds of several species over that of the commonly applied undecorated TiO2 nanobelts. The improved gas sensing properties are attributed to the pronounced electron transfer between the hierarchical nanostructures and the absorbed oxygen species as well as to the heterojunctions of the SnO2 nanospheres to the TiO2 nanobelts which provide additional reaction rooms. The results represent an advance of hierarchical nanostructures in further enhancing the functionality of gas sensors, and this facile method could be applicable to many sensing materials.