Sensitive and selective acetone sensor based on Gd doped WO3/reduced graphene oxide nanocomposite

Abstract

Abstract A sensitive and selective acetone sensor based on Gd doped WO3/reduced graphene oxide, a novel nanocomposite, has been reported in this paper. To begin with, pure and Gd-doped (2, 4, 6 and 8 mol%) WO3 nanostructures exhibiting nanoplate type morphology were synthesized using a room temperature simple acid precipitation method without use of any template or surfactant. The gas sensing measurements were performed on pure and Gd doped WO3 nanostructures to select the optimum operating temperature and dopant concentration. The sensor with optimized doping of 6 mol% Gd has been found to be quite selective to acetone and ethanol vapours while operating at optimum temperature of 350 °C. Further improvement in sensitivity, selectivity and lowering of operable temperature has been achieved by incorporation of reduced graphene oxide (RGO) into 6 mol% Gd doped WO3 nanostructures. The novel material thus developed has exhibited significant improvement in sensing response and became selective to acetone at markedly reduced optimum operable temperature to 200 °C. The achieved sensor characteristics could be attributed to change in electrical conductivity of RGO based nanocomposite due to superior electronic conductivity of RGO sheets and the interaction between n-type WO3 and p-type RGO.