Unraveling the impact of Ag dopant in Zn–In–S colloidal nanocrystals for boosting visible-light-driven photocatalytic CO2 reduction†

The development of durable and effective photocatalysts is significant for realizing efficient photocatalytic CO₂ conversion. In this work, heteroatom doped Zn–In–S colloidal nanocrystals are fabricated via a facile method, which can be utilized for photocatalytic CO₂ reduction under visible light in the presence of triethanolamine. Among various dopants, Ag shows the most effectiveness for improving the photocatalytic CO₂ reduction performance of Zn–In–S colloidal nanocrystals. The optimized Ag doped Zn–In–S colloidal nanocrystals with doping amount of 1.13 wt% exhibit the highest photocatalytic CO₂ reduction performance with a CO evolution rate of 30.29 μmol h⁻¹, achieving high selectivity of 96.06%. The photocatalytic mechanism study indicates that increasing the doping amount of Ag in Zn–In–S colloidal crystals would result in the improved visible light harvesting ability, increased charge carrier lifetime and weakened reduction potential of electrons, which exert a synergistic effect on the CO₂ photoreduction.