Interfacial lattice matched sub-2 nm RuO2 on rutile TiO2 nanorod for visible light driven CO2 conversion to CH4

Abstract

Photocatalytic CO₂ reduction reaction is regarded as a potential strategy to convert greenhouse gases into valuable chemicals. However, achieving photocatalysts with high efficiency and target product selectivity under visible light still faces great challenges. Herein, sub-2 nm RuO₂@TiO₂ (RTO) nanorods with lattice matching interface are rationally designed and prepared via a hydrothermal reaction step-by-step. Due to the strong interaction of the lattice-matched interface with the Ru-O-Ti bond, new energy levels have emerged at the interface, leading to effective visible light absorbance. Moreover, the photo-generated electrons could be transferred to the RuO₂ efficiently via the lattice-matched interface. As a result, the RTO photocatalyst exhibits superior CO₂-to-CH₄ conversion performance of 15.6 µmol g⁻¹ with a selectivity of 87.9% under visible light irradiation. Density functional theory (DFT) calculation reveals that the energy barrier of CO* to CO is significantly higher than that of *CHO, resulting in the preferential production of CH₄. This work provides an effective strategy for designing photocatalyst with promoted visible light absorption and improved product selectivity.