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.