Tailoring Advanced N‐Defective and S‐Doped g‐C3N4 for Photocatalytic H2 Evolution

Abstract

AbstractAlthough challenges remain, synergistic adjusting various microstructures and photo/electrochemical parameters of graphitic carbon nitride (g‐C3N4) in photocatalytic hydrogen evolution reaction (HER) are the keys to alleviating the energy crisis and environmental pollution. In this work, a novel nitrogen‐defective and sulfur‐doped g‐C3N4 (S‐g‐C3N4‐D) is designed elaborately. Subsequent physical and chemical characterization proved that the developed S‐g‐C3N4‐D not only displays well‐defined 2D lamellar morphology with a large porosity and a high specific surface area but also has an efficient light utilization and carriers‐separation and transfer. Moreover, the calculated optimal Gibbs free energy of adsorbed hydrogen (ΔGH*) for S‐g‐C3N4‐D at the S active sites is close to zero (≈0.24 eV) on the basis of first‐principle density functional theory (DFT). Accordingly, the developed S‐g‐C3N4‐D catalyst shows a high H2 evolution rate of 5651.5 µmol g−1 h−1. Both DFT calculations and experimental results reveal that a memorable defective g‐C3N4/S‐doped g‐C3N4 step‐scheme heterojunction is constructed between S‐doped domains and N‐defective domains in the structural configuration of S‐g‐C3N4‐D. This work exhibits a significant guidance for the design and fabrication of high‐efficiency photocatalysts.