Storing renewable energy from photocatalysis of water is an attractive solution to the intermittency problem faced by many alternative energy sources. Due to its high gravimetric energy density (142 MJ/kg) and zero emission use, hydrogen is considered one of the most promising clean energy carriers. It can be produced by different methods, including steam methane reforming of natural gas, coal gasification, electrolysis of water, and photoelectrochemical and photocatalytic methods of water splitting. Among these, photocatalytic hydrogen production is one of the better options to produce green hydrogen in pure form without any greenhouse gases from water in the presence of catalyst and sunlight. The research community has been focusing on finding the optimal materials for photocatalytic Hydrogen production for decades. In recent times, search for photocatalytic materials have intensified as green hydrogen production has become one of the priorities to tackle the energy demand. TiO₂ has been widely used in literature as one of the options. In this study, focus on different wt.% of NiS₂ embedded TiO₂ nanocomposite to produce hydrogen, which were synthesized by a facile hydrothermal method. A comparison study on photocatalytic hydrogen production under extended solar irradiation for different wt.% of NiS₂ embedded TiO₂ nanocomposite is carried out. The materials were characterized by X-ray diffraction spectroscopy, scanning electron microscopy, diffuse reflectance spectroscopy, and electrochemical impedance spectroscopy. The amount of hydrogen produced was measured by Gas Chromatography (GC) with a Thermal conductivity detector (TCD). The optimum amount of hydrogen, 4.185 mmolg^-1, was produced with 15 wt.% of NiS₂/TiO₂ nanocomposite. The higher activity can be correlated with the well separated electron-hole pairs. NiS₂/TiO₂ composite emerges as a promising candidate for photocatalytic Hydrogen production.

Keywords: hydrogen, photocatalysis, TiO₂