Tuning of the Oxygen Species Linker on the Surface of Polymeric Carbon Nitride to Promote the Photocatalytic Hydrogen Evolution Performance.

Abstract

Polymeric carbon nitrides (CNs) have been identified as attractive photocatalysts owing to their comparatively low cost and facile modification of their electronic structure. Herein, we report an effective strategy to tune the surface oxygen species linking site of polymeric CN, achieving more effective charge separation. A high photocatalytic hydrogen production rate of approximately 10225 μmol h-1 g-1 under visible light irradiation (λ>420 nm) and an impressive apparent quantum efficiency (AQE) of 5.7 % at 430 nm were recorded. Specifically, thermal treatment under a H2 and then an air atmosphere allowed the oxygen species linker on the surface of CN to be changed from -C=O to N=C-OH and then -C-O-C-, resulting in unbalanced charge distribution, which significantly enhanced the photogenerated charge separation, further contributing to the high hydrogen production performance. This linker regulation strategy may provide a new path for the development of highly efficient photocatalysts.