“Environmental phosphorylation” boosting photocatalytic CO2 reduction over polymeric carbon nitride grown on carbon paper at air-liquid-solid joint interfaces

Abstract

The limited CO2 content in aqueous solution and low adsorption amount of CO2 on catalyst surface lead to poor photocatalytic CO2 reduction activity and selectivity. Herein, the design and fabrication of a novel photocatalytic architecture is reported, accomplished via chemical vapor deposition of polymeric carbon nitride on carbon paper. The as-obtained samples with a hydrophobic surface exhibit excellent CO2 transport and adsorption ability, as well as the building of triphase air-liquid-solid (CO2-H2O-catalyst) joint interfaces, eventually resulting in the inhibition of H2 evolution and great promotion of CO2 reduction with a selectivity of 78.6%. The addition of phosphate to reaction environment makes further improvement of CO2 photoreduction into carbon fuels with a selectivity of 93.8% and an apparent quantum yield of 0.4%. This work provides new insight for constructing efficient photocatalytic architecture of CO2 photoreduction in aqueous solution and demonstrates that phosphate could play a key role in this process.