Cocatalyst free nickel sulphide nanostructure for enhanced photocatalytic hydrogen evolution

摘要

Metal chalcogenides are highly active, inexpensive, and earth-abundant materials for photocatalytic hydrogen evolution. This work presents cocatalyst-free Nickel Sulphides (alpha and beta phases) nanostructures for photocatalytic hydrogen generation. NiS nanostructures are synthesized by the solvothermal method by varying the water to ethanol ratio. The synthesized sample has shown an optical bandgap of 1.83 eV, which is favorable for H-2 generation. X-ray diffractometer (XRD) patterns confirm the formation of hexagonal and rhombohedral crystal structures with high phase purity for both NiS-alpha and NiS-beta nanostructures. The multifaceted regular-shaped morphology with 50 nm sized particles was confirmed by high-resolution transmission electron microscopy (HR-TEM). The photocatalytic H-2 generation studies reveal that the NiS-alpha phase exhibited better H-2 generation activity of 13.413 m mol h(-1)g(-1) than the NiS-beta phase of 12.713 m mol h(-1)g(-1) under UVeVis light irradiation without any cocatalyst. (C) 2021 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.