Carbon Self‐Doping Induced Activation of n–π* Electronic Transitions of g‐C3N4 Nanosheets for Efficient Photocatalytic H2 Evolution

Abstract This paper reports a facile one‐pot synthesis strategy to prepare carbon self‐doped g‐C 3 N 4 (C‐g‐C 3 N 4 ) nanosheets by using supramolecular networks consisting of cyanuric acid, ethylene glycol (EG), and melamine (CEM) bonded through hydrogen bonding as the thermal polycondensation precursor, in which EG serves as a solvent for cyanuric acid and melamine, and as a source of the doped carbon simultaneously. The threedimensional structure of CEM resulted in the distortion of C‐g‐C 3 N 4 , which is capable of motivating the n–π* electronic transition involving the N lone pairs to give an additional absorption region from 450 to 600 nm. The hydrogen evolution rate of C‐g‐C 3 N 4 reaches 73.09 μmol h −1 , which is about 15 times of that over the g‐C 3 N 4 obtained from direct thermal polycondensation of melamine owing to its extended light harvesting and faster separation of photogenerated electrons and holes.