Co(OH)2 water oxidation cocatalyst-decorated CdS nanowires for enhanced photocatalytic CO2 reduction performance

Abstract

Photocatalytic CO₂ reduction is a promising technology to resolve the greenhouse effect and energy crisis. In this work, a Co(OH)₂ nanoparticle decorated CdS nanowire (Co(OH)₂/CdS) based heterostructured photocatalyst was prepared via a solvothermal and subsequent co-precipitation method, and it was used for photocatalytic CO₂ reduction. The optimal Co(OH)₂/CdS photocatalyst achieves a CO production rate of 8.11 μmol g⁻¹ h⁻¹ under visible light irradiation (λ > 420 nm), which is about 2 times higher than that of bare CdS. The experimental results show that a Co(OH)₂ cocatalyst possesses a great capability of consuming holes, which promotes the oxygen-producing half-reaction and accelerates charge separation, thus enhancing the CO₂ photoreduction performance of CdS. Notably, without using complex synthesis processes, hazardous substances or expensive ingredients, Co(OH)₂/CdS shows high light absorption, efficient charge separation and complete CO product selectivity. This work offers a new pathway for the construction of cost-effective photocatalytic materials to achieve highly efficient CO₂ reduction activity by the integration of a Co(OH)₂ cocatalyst.