In situ metal-organic framework-derived c-doped Ni3S4/Ni2P hybrid co-catalysts for photocatalytic H2 production over g-C3N4 via dye sensitization

Controlled integration of metal-based sulfides with phosphides possessing strong coupling effects is a promising way to accelerate electron transfer by modulating the electronic structures of the host species. In this work, a c-doped Ni3S4/Ni2P (C@Ni3S4/Ni2P)hybrid co-catalyst produced by in situ sulfuration and phosphidation of Ni-MOF was decorated on g-C3N4 and subsequently used for photocatalytic H-2 evolution under visible-light irradiation. Among the prepared composites tested herein, the optimized g-C3N4/C@Ni3S4/Ni2P-30 composite showed the highest H-2 evolution rate (14.49 mmol g(-1) h(-1))with 1.0 mmol L- of Eosin Y (EY)-sensitization, which is 10 times higher than that of pristine g-C3N4 (1.33 mmol g(-) h(-)). The enhanced photocatalytic activity of this composite can be attributed to: (i)electronic interactions between Ni2P and Ni3S4 (which synergistically increased the electron transfer rate)and (ii)staggered band alignment of excited-stated EY, g-C3N4, Ni3S4, and Ni2P. This work may provide some perspectives for utilization of MOF-derived hybrid co-catalysts as substitutes of noble metals for effective photocatalytic H-2 evolution. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.