Pushing the boundaries: enhancing TiO2 performance for hydrogen evolution under visible light photocatalysis by incorporating RuO2

Abstract

A highly efficient and porous TiO₂–RuO₂ nanocomposite was fabricated via a one-pot solvothermal route. Varying the ruthenium content in the synthesis revealed the importance of modifying synthesis conditions in achieving a highly porous and effective photocatalytic material. The results from the study show that an optimal weight of 20% ruthenium precursor in the TiO₂–RuO₂ nanocomposite demonstrated enhanced photocatalytic properties compared to other compositions. The nanocomposite exhibited high performance in the H₂ gas evolution reaction due to the synergistic effect of TiO₂ and RuO₂, enhancing charge transfer and improving light absorption. The TiO₂–RuO₂-20 exhibited double reduction potential and low solution resistance. As a result of the reduced band gap, improved light absorption capability, and low electron–hole recombination, TiO₂–RuO₂-20 yielded a significant amount of hydrogen gas, 1794.8 μmol g⁻¹ h⁻¹, over 3 h of activity under visible light. This amount far exceeded the yield observed for RuO₂ alone (21.9 μmol g⁻¹ h⁻¹) and the commercially available TiO₂ (246.4 μmol g⁻¹ h⁻¹). This confirms the contribution and effectiveness of a low amount of ruthenium required in fabricating highly effective TiO₂–RuO₂ catalysts for photocatalytic hydrogen evolution. The single-step, low-cost solvothermal method offers a significant advantage in obtaining cost-effective materials for efficient hydrogen generation.