Enhancing photocatalytic CO₂ reduction performance of In(OH)₃ via bismuth isomorphic substitution

Foreigner element doping is one of effective strategies to promote photocatalytic reaction. Herein, a convenient one-step solvothermal method is applied to enable the isomorphic substitution of In³⁺ in In(OH)₃ by Bi³⁺. The composition and microstructure of the photocatalysts were mainly obtained by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy revealed the optical properties of photocatalysts. The surface properties of photocatalysts were mainly characterized by X-ray photoelectron spectroscopy (XPS). Theoretical calculations were used to reveal the reaction mechanism. The results indicated that CO production rate and selectivity of Bi³⁺ doped In(OH)₃ are much higher than that of the pure In(OH)₃, which could be attributed to the extended solar spectral response, the enhanced CO₂ adsorption capacity and the accelerated photogenerated carriers separation. The current work verifies the potential application of isomorphic substitution as an efficient route for solar fuel production.