Phenyl-incorporated carbon nitride photocatalyst with extended visible-light-absorption for enhanced hydrogen production from water splitting

摘要

Developing and employing photocatalysts with extended visible-light-absorption has emerged as a fundamental issue for the enhanced capability of photocatalytic H-2 evolution from water splitting. Herein, a wide-spectrum light-responsive phenyl-grafted carbon nitride photocatalyst was synthesized. It was found that benzonquanmine-derived g-C3N4 (BCN) exhibits significantly extended light absorption (similar to 670 nm) compared with conventional melamine-derived g-C3N4 (MCN). Correspondingly, the photocatalytic H2-evolution rate of BCN (2846 lmol h(-1) g(-1)) is five times as that of MCN under visible-light irradiation. Particularly, an impressive H-2-evolution rate of 58 lmol h(-1) g(-1) could be achieved on BCN even under light irradiation beyond 620 nm. The outstanding photocatalytic H-2-evolution performance could be not only attributed to the enriched photons generated from the enhanced solar energy harvesting, but also to the distinctly inhibited rapid recombination of photogenerated electron-hole pairs resulting from the incorporation of phenyl groups. This work furnishes a new train of thought for the designing of carbon-nitride-based photocatalysts with enhanced capability of visible-light-utilization.

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