Noble metal-free NiSe2 nanosheets decorated MIL-53(Fe) microrods with highly efficient visible-light driven photocatalytic H2 generation

In this study, a series of noble metal-free NiSe2 nanosheets decorated MIL-53(Fe) microrods for photocatalytic H-2 evolution were fabricated through a two-step solvothermal route. The morphology, structure, composition and photoelectric properties of the synthesized NiSe2/MIL-53(Fe) composites were examined by various characterization techniques. It was revealed that the photocatalytic H-2 evolution of MIL-53(Fe) was significantly enhanced by loading NiSe2 nanosheets. As an efficient co-catalyst, the optimal NiSe2 loading was determined to be 1.0 wt%, giving a maximum H-2 production rate of 10.31 mmol h(-1) g(-1) under visible light illumination, which was 11.1 times higher than that of bare MIL-53(Fe) (0.93 mmol h(-1) g(-1)) and also exceeded that of Pt/MIL-53(Fe). The apparent quantum efficiency of 1.0-NiSe2/MIL-53(Fe) reached to 10.8% at 420 nm even without any precious metal. Moreover, the photocatalytic activity of the NiSe2/MIL-53(Fe) hybrids remained durable even after five photocatalytic cycles. The possible mechanism on enhanced photocatalytic activity of NiSe2/MIL-53(Fe) hybrids was proposed and verified by PL spectroscopy and photocurrent measurements. This work demonstrates for the first time the great potential of NiSe2 as a precious-metal free co-catalyst for photocatalytic H-2 generation. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.