Photothermal Reduction of Carbon Dioxide Using Magnetite Photocatalyst

One promising approach to achieving sustainable energy while simultaneously addressing various environmental issues is to utilize solar-driven transformation of the greenhouse gas CO2 into valuable chemical fuels. The main obstacle in achieving this goal has consistently been the identification of cost-effective, stable, and non-toxic photoactive materials that can efficiently convert CO2 into chemical fuels. Photothermal catalysis offers a viable solution to address the challenges related to sunlight absorption and low quantum efficiency often encountered in conventional photocatalysts. In this study, we used a magnetite catalyst for the photothermal reduction of CO2. Various characterization techniques, including PXRD, TEM, and XPS, were employed to confirm the catalyst phase, crystallinity, particle size, and the electronic structure of the magnetite catalyst. The results of the photothermal conversion of carbon dioxide revealed that carbon monoxide was the only product, with a selectivity of 100%. Furthermore, the Fe3O4 catalyst produced significantly higher CO under high-intensity illumination (2076 μmolgcat−1h−1) than in the dark (820 μmolgcat−1h−1) under the same temperature of 315 °C. The activation energy obtained for the tests conducted under high-intensity illumination was lower than that obtained in the dark. The use of photothermal catalysts such as Fe3O4 to drive useful chemical reactions such as CO2 conversion to useful products contributes to advancing the field of sustainable energy and marks a significant stride toward realizing real solutions for mitigating climate change.