Pt-modified BiVO4 nanosheets for enhanced acetone sensing

Two-dimensional (2D) BiVO4 nanosheets (NSs), featuring distinctive chemical properties and dangling-bond-rich surfaces, are promising for developing high-performance gas sensors. However, the previously reported 2D BiVO4 NSs-based devices suffer from a low responsivity and poor selectivity. Here, catalytic metal (Pt) nanoparticles (NPs) are functionalized on the surface of BiVO4 NSs to improve the sensing ability. Comparative investigations verify the significant enhancement in acetone sensing after Pt modification. The Pt NPs-loaded BiVO4 exhibits a response of 12.5–100 ppm acetone, which is 3.2 times higher than that of pure BiVO4 sensor. Besides, the Pt-BiVO4 sensor possesses better selectivity and lower detection limit. From both the experimental results and density functional theory (DFT) calculation, the effects of Pt modification are elucidated as a synergy of chemical and electronic sensitization. The loading of Pt benefits the thickening of electron depletion layer, and accumulating and activating the acetone molecules, which accelerate the reaction between acetone and chemisorbed oxygen species, resulting in enhanced sensing performance. This work gives deep insights into the effects of noble metal modification on metal oxide-based sensing material and could serve as a guideline for further designing novel high-performance sensing materials.