Hydrogen gas which is used as a fuel to generate electricity can be produced by water splitting through a photoelectrochemical reaction process. The synthesis of TiO2/CoS composites was carried out to form p-n junction between TiO2 and CoS which prevents electron-hole recombination to increase the photoelectrochemical activity of TiO2. In this research, thin film TiO2/CoS composites were synthe…