Design of Bimetallic Active Sites via Transition Metal Doping JANUS In2S2X for Highly Selective Photocatalytic CO2 Reduction

A rational design strategy for active sites on the catalyst surface can effectively enhance CO2 reduction reaction (CO2RR) selectivity. Transition metal atoms from the fourth (Sc–Ni) and fifth (Y–Mo, Ru–Pd) periods were doped onto the In2S2X (X = Se, Te) surface to control bimetallic active sites. The study showed that the d-band center’s position of the dopant atom significantly influences CO2RR selectivity. Cations with positive d-band centers further from the Fermi level are more inclined towards CH2O, while those with negative d-band centers closer to the Fermi level favor HCOOH; cations with d-band centers near the Fermi level exhibit a strong preference for CH3OH. This study systematically elucidates the intrinsic mechanisms and offers a significant theoretical foundation for developing highly selective photocatalysts.