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 CO 2 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. The incorporation of Bi atoms into In(OH) 3 lattice introduced many defects, which narrowed the band gap, extended the solar spectral response range, inhibited the recombination of photocarriers and exposed more active sites. As a result, much higher activity for CO 2 photoreduction toward CO with H 2 O is achieved. [Display omitted] • Bi3+ doped In(OH) 3 photocatalysts are fabricated via a one-pot solvothermal method. • Introduction of Bi3+ remarkably promotes specific surface area and formation of In vacancies. • Synergetic effects of Bi3+ and In vacancies improve light absorption and charge separation. • Bi3+ isomorphic substitution for In3+ enhances CO 2 reduction with improving CO selectivity. [ABSTRACT FROM AUTHOR]