Heterostructure based on exfoliated graphitic carbon nitride coated by porous carbon for photocatalytic H2 evolution

In this contribution, the heterostructure based on exfoliated graphitic carbon nitride (ex-gCN) coated by a porous carbon layer was fabricated by a simple approach and tested as a photocatalyst for hydrogen evolution under simulated solar light illumination. Bulk-gCN was firstly exfoliated and annealed under a hydrogen atmosphere in carefully selected conditions. The catalyst with the highest photoactivity was fabricated at 400 degrees C for 4 h. This material exhibited about a 23-fold higher amount of photogenerated hydrogen (18.2 mmol/ g) compared to reference ex-gCN (0.8 mmol/g). Boosted photoactivity could be attributed to the (i) highly developed Specific Surface Area leading to more active sites on the surface due to the porous carbon layer, (ii) better transfer, and separation of photogenerated car-riers, and (iii) sufficient suppression of the recombination process. Moreover, the mechanism of photocatalytic H2 evolution from water splitting based on a full physico-chemical characterization of the studied materials was proposed.(c) 2022 The Authors. Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/).