Efficient photoreduction of CO2 to CO by Co-ZIL-L derived NiCo–OH with ultrathin nanosheet assembled 2D leaf superstructure†

Abstract

The photocatalytic reduction of CO₂ into valuable chemicals and fuels is considered a promising solution to address the energy crisis and environmental challenges. In this work, we introduce a Co-ZIL-L mediated in situ etching and integration process to prepare NiCo–OH with an ultrathin nanosheet-assembled 2D leaf-like superstructure (NiCo–OH UNLS). The resulting catalyst demonstrates excellent photocatalytic performance for CO₂ reduction, achieving a CO evolution rate as high as 309.5 mmol g⁻¹ h⁻¹ with a selectivity of 91.0%. Systematic studies reveal that the ultrathin nanosheet structure and 2D leaf-like architecture not only enhance the transfer efficiency of photoexcited electrons but also improve the accessibility of active reaction sites. Additionally, the Ni–Co dual sites in NiCo–OH UNLS accelerate CO₂ conversion kinetics by stabilizing the *COOH intermediate, significantly contributing to its high activity. This work offers valuable insights for designing advanced photocatalysts for CO₂ conversion.