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‐C3N4 (C‐g‐C3N4) 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‐C3N4, 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‐C3N4 reaches 73.09 μmol h−1, which is about 15 times of that over the g‐C3N4 obtained from direct thermal polycondensation of melamine owing to its extended light harvesting and faster separation of photogenerated electrons and holes.