Mo doped BiVO4 gas sensor with high sensitivity and selectivity towards H2S

Multinary metal oxide semiconductor (MOS) based gas sensors have great potentials to attain outstanding selectivity comparing with binary metal oxides owing to their abundant structure types. While, doping is a very versatile route to modify the electronic structure of MOSs and enhance the sensing response to specific gas. Inspired by the encouraging results of Mo doped in the BiVO4 photoanodes for water splitting, herein, the sensing properties of Mo doping effect in BiVO4 were investigated systematically for the first time. The results indicated that the 0.2 at% Mo-doped BiVO4 possess the best gas sensing properties with high sensitivity (S = 16.7), superior selectivity, fast response to 20 ppm H2S at 150 °C. Further analysis indicates that the incorporation of Mo6+ into BiVO4 could adjust the material conductivity, induce the oxygen vacancy and increase the chemisorbed oxygen species. These results suggest that doping Mo into BiVO4 is a promising method to attain superior gas-sensing properties.