Rationally Designed Copper-Modified Polymeric Carbon Nitride as a Photocathode for Solar Water Splitting

Polymeric carbon nitride has been considered to be an active photocathode for catalyzing the generation of H ₂ through water splitting. However, the application of this material in photoelectrochemical cells remains a challenge owing to the intrinsically sluggish kinetics of charge separation. Herein, a facile salt-melt method is developed for fabricating Cu-modified polymeric carbon nitride as an effective photocathode material for solar water splitting. Various characterization data confirm that Cu-modified polymeric carbon nitride contains both free CuCl, derived from precursors, and coordinated Cu species incorporated into the polymeric carbon nitride, which can generate type-II heterojunctions. This special heterojunction energy structure contributes to a significantly enhanced photocurrent density for hydrogen evolution. The proposed strategy for synthesizing the Cu-modified polymeric carbon nitride can stimulate research for the development of highly efficient visible-light-active photocathodes.