Synchronous activation of Ag nanoparticles and BiOBr for boosting solar-driven CO2 reduction

Abstract

Artificial photosynthesis of valuable chemicals from CO2 is a potential way to achieve sustainable carbon cycle. The CO2 conversion activity is still inhibited by the sluggish charge kinetics and poor CO2 activation. Herein, Ag nanoparticles coupled BiOBr have been constructed by in-situ photoreduction strategy. The crafting of interface between Ag nanoparticles and BiOBr nanosheets, achieving an ultra-fast charge transfer. The BiOBr semiconductor excited electrons and plasmonic Ag nanoparticles generated high-energy hot electrons synchronous accelerates the C=O double bond activation. Thus, the optimized Ag/BiOBr-2 heterostructure shows excellent CO2 photoreduction activity with CO production of 133.75 and 6.83 µmol/g under 5 h of 300 W Xe lamp and visible light (λ > 400 nm) irradiation, which is 1.51 and 2.81 folds versus the pristine BiOBr, respectively. The mechanism of CO2 photoreduction was in-depth understood through in-situ FT-IR spectrum and density functional theory calculations. This study provides some new perspectives into efficient photocatalytic CO2 reduction.