Unraveling the Polarization Effect on P-Doped NiO Nanosheets for Efficient Photocatalytic CO ₂ Reduction

Sluggish charge transfer and a high surface reaction barrier are bottleneck problems of photocatalytic CO 2 reduction. The search for strategies that can accelerate charge dynamics and lower the surface reaction barrier synchronously remains challenging. Here, we put forward a surface polarization strategy to promote photocatalytic CO 2 reduction over NiO nanosheets by phosphorus (P) elemental doping. The as-prepared P-doped NiO nanosheets (P–NiO) exhibit superior photocatalytic CO 2 -to-syngas conversion performance with tunable ratios of CO/H 2 when accepting photogenerated electrons from both [Ru(bpy) 3 ]Cl 2 and CdSe/S colloidal crystal light absorbers. It is revealed that doping P in NiO nanosheets can modulate the polarization to promote the transfer of photoexcited electron–hole pairs and also upshift the d-band center of the Ni active site for facilitating the adsorption of reactant and lowering the activation energy barriers of both the *COOH and H* intermediates, thus promoting the photocatalytic CO 2 -to-syngas conversion reaction.