Defect-rich selenium doped graphitic carbon nitride for high-efficiency hydrogen evolution photocatalysis

Graphitic carbon nitride (g-C3N4) has been demonstrated as a promising non-metal material for photocatalytic hydrogen evolution (PHE), while its photocatalytic activity is greatly limited due to the narrow visible light response-ability and the intrinsic severe charge deep trapping and recombination effects. Herein, a co-functionalized g-C3N4 system by Se doping and nitrogen vacancies modification is developed through a Se vapor assisted-chemical vapor deposition synthetic strategy. Advanced characterization results revealed that Se dopants promote the visible-light absorption ability of g-C3N4, while nitrogen defects-induced shallow trap states are constructive to improving charge separation/transportation efficiency by effectively retarding the detrimental charge deep trapping and recombination. As a result, the synergistic effect of the Se dopants and nitrogen defects leads to a highly efficient PHE performance of g-C3N4. The integrated engineering strategy and mechanism understanding provided in this work may offer new insights into developing other novel photocatalysts for various applications.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.