biostudies-literatureUnknown16(4)Saleem SThis study demonstrates the synthesis and characterization of a NiS <sub><i>x</i></sub> /NiO/MoS<sub>2</sub> (<i>x</i> = 1, 2) heterostructure using a hydrothermal method, demonstrating superior performance for the hydrogen evolution reaction (HER) in 1 M H<sub>2</sub>SO<sub>4</sub>. X-ray diffraction (XRD) confirmed the presence of cubic NiO, mixed NiS and NiS<sub>2</sub> phases, and hexagonal MoS<sub>2</sub>, while scanning electron microscopy (SEM) revealed an interconnected nanosheet morphology with Ni, S, Mo, and O elements verified by energy-dispersive X-ray (EDX) spectroscopy. Fourier-transform infrared (FTIR) spectroscopy identified Ni-O, Ni-S, and Mo-S bonds, and UV-visible spectroscopy indicated a reduced bandgap of 2.81 eV for the composite. The composite achieved a low overpoteRSC advances3261-3275https://www.ebi.ac.uk/biostudies/studies/S-EPMC12802422biostudies-literatureNiS <sub><i>x</i></sub> /NiO/MoS<sub>2</sub> heterostructure for enhanced hydrogen evolution in acidic media and supercapacitor electrode applications.PMC12802422Khan MSardar BNoor ISaleem SSalman MfalseNiS <sub><i>x</i></sub> /NiO/MoS<sub>2</sub> heterostructure for enhanced hydrogen evolution in acidic media and supercapacitor electrode applications.This study demonstrates the synthesis and characterization of a NiS <sub><i>x</i></sub> /NiO/MoS<sub>2</sub> (<i>x</i> = 1, 2) heterostructure using a hydrothermal method, demonstrating superior performance for the hydrogen evolution reaction (HER) in 1 M H<sub>2</sub>SO<sub>4</sub>. X-ray diffraction (XRD) confirmed the presence of cubic NiO, mixed NiS and NiS<sub>2</sub> phases, and hexagonal MoS<sub>2</sub>, while scanning electron microscopy (SEM) revealed an interconnected nanosheet morphology with Ni, S, Mo, and O elements verified by energy-dispersive X-ray (EDX) spectroscopy. Fourier-transform infrared (FTIR) spectroscopy identified Ni-O, Ni-S, and Mo-S bonds, and UV-visible spectroscopy indicated a reduced bandgap of 2.81 eV for the composite. The composite achieved a low overpote2026-01-01T00:00:00Z2026 Jan2026-06-11T04:59:35.151Z2026-06-11T03:07:45.609ZS-EPMC128024224154121810.1039/d5ra06931a