Photocatalytic and electrochemical water splitting have received much attention in the production of green hydrogen from water on a large scale. Many challenges still remain in improving energy conversion efficiency, such as utilizing photons for hydrogen production to enhance the reaction efficiency at any given wavelength, increasing the lifetime and reducing the cost of catalytic materials. Recently, transition metal chalcogenides have been utilized for a variety of applications due to their indirect band gaps, optoelectronic behavior, and their stability. Therefore, herein, we synthesized different metalchalcogenides (MS₂: M = Co, Ni, Sn) embedded with TiO₂ that form nanocomposites by the facile hydrothermal method for water splitting. The crystallinity and phases of the prepared materials were confirmed by X-Ray diffractive spectra; the morphology of the particles was studied by Scanning Electron Microscopy; and their superior catalytic performance in electrochemical and photocatalytic activity were examined using electrochemical characterization and photocatalytic experiments, respectively. In electrochemical processes, compared with bare TiO₂, 10 wt.% metalchalcogenide embedded composites, CoS₂/TiO₂, SnS₂/TiO₂, and NiS₂/TiO₂, exhibited high current densities with low Tafel slope values in HER (hydrogen evolution reaction) and OER (oxygen evolution reaction), whereas the maximum hydrogen evolution attained with the 10wt% NiS₂/TiO₂ nanocomposite (3603 µmol/g) when it was used as photocatalyst. These results show that metalchalcogenide (MS₂) embedded TiO₂ nanocomposites are potential candidates to be used as efficient electro and photocatalysts for the water splitting process.

Keywords: metalchalcogenides, titania, water splitting