Proton exchange membrane (PEM) electrolyzer stands out for its superior hydrogen purity and current densities compared to other electrolyzers. However, the use of noble metals as catalysts in the membrane electrode assembly (MEA) poses a significant challenge to its large-scale commercialization. Transition metals are being explored as viable catalysts for hydrogen production due to their unique electronic structure and abundance in the Earth's crust. Nickel nanoparticles (Ni-NPs) emerge as a promising candidate for PEM electrolyzers due to their low cost, abundance, and excellent catalytic activity in both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this study, Ni-NPs catalysts were synthesized using radio frequency (RF) sputtering and chemical methods at various deposition thicknesses directly on nitrogen-enriched carbon fiber (g-CN) cathodes for water electrolysis. Morphological and structural analysis of the prepared electrodes was conducted using x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), and scanning electron microscopy (SEM). Electrochemical activity of the HER performance was investigated using three-electrode systems and cyclic voltammetry (CV).The results reveal the catalytic activity of Ni-NP embedded in g-CN and the reaction rate for HER compared to pristine g-CN by controlling the particle size, enlarging the active sites, and boosting charge transfer properties, and compare the catalytic efficiency for the two manufacturing routes. This contribution provides a cheaper and stable HER electrocatalyst that can be used in water splitting systems for efficient hydrogen generation.