BiOCl with multiple active sites for CO2 reduction under visible light

Preparation of BiOCl with abundant active sites via PVP-assisted aqueous/solvothermal method and Its application in photocatalytic CO 2 reduction. • Increased active site facilitates CO 2 adsorption and activation. • The mechanism of action of EG and PVP in the BiOCl crystal growth process has been proposed. Photocatalytic CO₂ conversion represents a promising green approach to mitigate carbon emissions, yet the fast recombination of photogenerated charge carriers severely restricts the catalytic efficiency of conventional photocatalysts. Rational surface and crystal engineering is therefore essential to address this issue. In this work, we report a facile solvothermal synthesis of BiOCl with enriched active sites, where EG and PVP act as co-regulators for crystal growth. The two additives sequentially coordinate with Bi³⁺, and the stronger competitive adsorption of PVP, together with the modulation effect of EG, collaboratively decreases grain size and drives the preferential exposure of catalytically favorable (110) facets. Spectroscopic characterizations confirm the surface functionalization by PVP. Benefiting from the optimized structure, the as-prepared BiOCl delivers a 1.6-fold increase in CO generation rate. More importantly, we establish the molecular-level synergistic mechanism of EG and PVP for (110) facet regulation, and clarify the underlying mechanism of photocatalytic CO 2 reduction over the as-obtained material. The synergistic effect of PVP and EG promotes the exposure of highly active crystal planes on the BiOCl surface. Simultaneously, PVP modification of BiOCl increases the surface charge density, collectively enhancing photocatalytic activity. Download: Download high-res image (189KB) Download: Download full-size image