Crystal Engineering of BiVO 4 for Photochemical Sensing of H 2 S Gas at Ultra‐low Concentration

We report a photochemical bismuth vanadate (BiVO 4 ) sensing material, which possesses a large proportion of (110) and (011) facets combined with the additional (111) facets, for the selective detection of ultra‐low concentration hydrogen sulfide (H 2 S) driven by visible light. Specifically, the obtained octadecahedron BiVO 4 (Octa‐BiVO 4 ) performs a high response value (67) and short response time (47.4 s) to 100 ppm H 2 S with good stability for nearly 100 days, as well as undisturbedness by moist air. With the combination of experimental and theoretical calculation results, the adsorption and carrier transfer behaviors of H 2 S molecules on the Octa‐BiVO 4 crystal surface are investigated. By adjusting the ratio of different crystal facets and controlling the facets with characteristic adsorption, we achieve improved anisotropic photoinduced carrier separation and high selectivity for a specific gas. Furthermore, this facial facet engineering can be extended to the synthesis of other sensing materials, offering huge opportunities for fundamental research and technological applications.