Ru-embedded 3D g-C3N4 hollow nanosheets (3D CNHNS) with proficient charge transfer for stimulating photocatalytic H2 production

Abstract

In the recent development of structured materials, efficient and low-cost materials are highly demanding for hydrogen production. In this work, novel 3D graphitic carbon nitride hollow nanosheets (CNHNS) with controlled morphology loaded with Ru for photocatalytic hydrogen production has been investigated. Compared to CN, CNHNS improves H2 evolution of 2 times due to hollow structure with higher light absorption and proficient separation of charges within 3D structure. The highest H2 evolution was attained over 3% Ru loaded CNHNS with yield rate of 1580 μmol g−1 h−1, which was 11.9 times higher than it was evolved over CNHNS and 15.1 times more than using CN, respectively. This obvious augmented photoactivity can be assigned to boosted charges separation in hollow structure, whereas, Ru further promoted the transfer of electrons. The performance of 3D Ru/CNHNS was further increased in an externally reflected solar system, which was 1.30 times more than using photoreactor without reflector. This was evidently due to increasing light intensity inside the reactor by reflecting light, thus, promoting quantum efficiency under the same source of light. The stability results further confirm continuous H2 evolution even after six cycles. Thus, newly developed method for synthesis of hierarchical 3D hollow structures and externally reflector solar photoreactor will provide new directions for hydrogen production systems.