The photocatalytic activity of titanium dioxide (TiO₂) nanoparticles toward hydrogen generation can be significantly improved via the loading of various metals e.g., Ru, Co, Ni as co-catalysts. The metal co-catalysts are loaded into TiO₂ nanoparticles via different deposition methods; incipient wet impregnation (Imp), hydrothermal (HT), or photocatalytic deposition (PCD). Among all of the tested materials, 0.1 wt% Ru–TiO₂ (Imp) provided the highest initial hydrogen catalytic rate of 23.9 mmol h⁻¹ g⁻¹, compared to 10.82 and 16.55 mmol h⁻¹ g⁻¹ for 0.3 wt% Ni–TiO₂ (Imp) and 0.3 wt% Co–TiO₂ (Imp), respectively. The loading procedures, co-catalyst metals type, and their loading play a significant role in elevating the photocatalytic activity of pristine TiO₂ semiconductors toward hydrogen generation. Redox transition metals e.g., Co and Ni exhibit comparable photocatalytic performance to expensive elements such as Ru.