Edge-Site-Rich Ordered Macroporous BiOCl Triggers CO Activation for Efficient CO2 Photoreduction

Abstract

Endowing a semiconductor with tunable edge active sites will effectively enhance catalytic performance. Herein, an edge-site-rich ordered macroporous BiOCl (BiOCl-P) with abundant dangling bonds is constructed via the colloidal crystal template method. The edge-site-rich ordered macroporous structure provides abundant adsorption sites for CO₂ molecules, as well as forms numerous localized electron enrichment areas, accelerating charge transfer. DFT calculations reveal that the dangling bonds-rich configuration can effectively reduce the CO₂ activation energy barrier, boost the CO double bond dissociation, and facilitate the proton electron coupling reaction. As a result, the BiOCl-P achieves a higher CO and CH₄ generation rate of 78.07 and 3.03 µmol g^-1 under 4 h Xe lamp irradiation in a solid-gas system. Finally, the CO₂ molecules' conversion process is further investigated by in situ Fourier-transform infrared spectroscopy. This work realizes a new avenue toward the design of vibrant semiconductors on the nanoscale to boost inert CO₂ photoreduction.

Keywords: CO2 photoreduction; CO activation; dangling bonds; edge-sites; ordered macroporous BiOCl.