Synergistic Photocatalytic CO₂ Reduction and Methanol Oxidation via Self-Photogenerated Oxygen Vacancy-Rich TiO₂ Nanostructures

Abstract

Integrating CO2 reduction with methanol oxidation presents a promising alternative strategy to store solar energy in CO2 reduction and produce more sustainable clean fuels and chemicals products, while identifying the carbon sources in the final products and elucidating the interactions between CO2 and methanol within such a mixed system is still particularly challenging. Herein, this study explores the efficiency of synergistic photocatalytic CO2 reduction and methanol oxidation via self-photogenerated oxygen vacancy-rich TiO2 nanostructures. Employing NMR spectroscopy and GC-MS analysis for (CO2)-C-13 isotope tracing samples, the exact carbon sources in both liquid and gas-phase products were clearly figure out. Moreover, through in situ DRIFTS analysis and DFT calculations, the crucial role of oxygen vacancies in enhancing catalytic activity and selectivity is revealed, and the CO2 reduction and methanol oxidation pathway on oxygen vacancy-rich TiO2 nanostructures are proposed. Consequently, our findings offer profound implications for advancing the field of synergistic photocatalytic processes, aiming to generate high-value chemical fuels sustainably.