Boosting charge transfer in Au-decorated B/K co-doped CN nanosheets towards enhanced photocatalytic CO2 reduction†
Abstract
Graphitic carbon nitride (CN)-based photocatalysts have received widespread attention for photocatalytic CO2 reduction. However, their activity is still insufficient due to the high recombination rate of photogenerated carriers and limited active sites. Here, we construct an Au nanoparticle modified B/K co-doped CN (Au/BKCN) photocatalyst for photocatalytic CO2 reduction. The B and K doping can accelerate exciton dissociation and promote the charge transport, thus effectively improving the separation efficiency of photo-induced electrons and holes. The Au nanoparticles not only promote the interfacial charge transfer but also provide more reactive sites for photocatalytic CO2 reduction, thereby synergistically improving photocatalytic CO2 activity. Thanks to the synergistic effects of Au loading and B/K co-doping, the optimal 1% Au/BKCN catalyst demonstrates a considerable CO production rate of 11.56 μmol g−1 h−1, which is about 7-fold enhanced compared to that of the bare CN. This work provides a new strategy to enhance the photocatalytic CO2 reduction activity of CN-based photocatalysts via element doping and cocatalyst decoration.