Enhancement of TiO2-Based Composite With Low Carbon-Based Component Ratio for Improved Hydrogen Generation via Photocatalytic Water Splitting

Abstract

Composite between titanium dioxide (TiO₂) and (reduced) graphene oxide (R(GO)) was prepared using a two-stage solvothermal synthesis with variable R(GO) mass ratios (0.01–5 wt.%). Partial reduction of the precursor solution of GO to RGO took place during the solvothermal synthesis at the elevated pressure and temperature conditions. The structural, morphological, and semiconducting characteristics of the obtained binary composites were determined and their capacity of hydrogen production via photocatalytic water splitting in the presence of triethanolamine (TEOA) as sacrificial agent under the simulated solar light irradiation was tested. Photocatalytic experiments have showed that even low mass ratios of R(GO) component (below 1 wt.%) can have a great influence on the photocatalytic activity and properties of the obtained material. The results showed that even a partial reduction of GO to RGO had a positive impact on the photocatalytic properties of the as-prepared materials. The composite with 0.05 R(GO) wt.% achieved the highest H₂ generation rate of 139 μmol/h/g and maintained high photostability. The incorporation of R(GO) into the TiO₂ matrix enhanced efficient charge separation, reduced the energy bandgap (E_g), and thus increased the visible light response (ΔE), leading to more effective hydrogen production.