Bi4O5Br2 co-modified with oxygen vacancy and Bi metal for efficient photothermal conversion of CO2 to C2 hydrocarbons

Photothermal catalytic reduction of CO 2 into high value-added C 2 hydrocarbon products is a promising method for efficient CO 2 conversion. However, current photocatalysts still encounter obstacles including limited photoabsorption range, rapid recombination of photogenerated carriers , and inadequate surface active sites. Herein, Bi 4 O 5 Br 2 co-modified with oxygen vacancy (OV) and metal bismuth (Bi) (Bi 4 O 5 Br 2 -OV@Bi) has been prepared to optimize these crucial issues. Bi 4 O 5 Br 2 -OV@Bi delivers a remarkably improvement in CO 2 photothermal conversion, reflecting by the notable increase in C 1 (CO and CH 4 ) and newly generated C 2 (C 2 H 4 and C 2 H 6 ) products compared to pristine Bi 4 O 5 Br 2 . In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) spectrometry reveals that OC−COH* intermediate promotes the C–C coupling for produce C 2 hydrocarbons. This study strengthens the understanding of metal modification and defect engineering for forming C 2 hydrocarbons on bismuth-based photocatalysts .