Enhancing photocatalytic water splitting: Comparative study of TiO2 decorated nanocrystals (Pt and Cu) using different synthesis methods

The use of light radiation to cause the dissociation of water into hydrogen (H2) gas has tremendous promise as a green method of hydrogen production. Herein, we reported a comparative study for the photocatalytic activity of TiO2 nanocomposite with two co-catalysts e.g., Pt or Cu nanocrystals (3-4 nm) using different synthesis procedures; incipient wet impregnation (Imp), hydrothermal (HT), or photo-deposition (PD) methods. The effect of catalyst mass loading percentages (0.1-1 wt.%) was investigated. The mass loading of 0.3 wt% for both cocatalysts exhibited the highest value of the generated hydrogen. Even without a precious metal such as Pt, Cu/TiO2 synthesized using the PD method provided an initial rate of 24 mmol h-1g 1, which is 3.5 and 1.4 times higher than the composite synthesized using HT and Imp methods. On the other hand, the highest rate for Pt cocatalyst was observed for the Imp method with a rate of 58 mmol h-1g 1 which was higher by 1.6 and 1.1 times than the composite synthesized using PD and HT methods, respectively. This study offers new perspectives on the significant influence of the co-catalyst deposition technique on the efficiency of photocatalysis for producing hydrogen through water splitting.