Elucidating oxygen evolution and reduction mechanisms in nitrogen-doped carbon-based photocatalysts

Solar-induced water oxidation reaction (WOR) for oxygen evolution is a critical step in the transformation of Earth's atmosphere from a reducing to an oxidation one during its primordial stages. WOR is also associated with important reduction reactions, such as oxygen reduction reaction (ORR), which leads to the production of hydrogen peroxide (H2O2). These transitions are instrumental in the emergence and evolution of life. In this study, transition metals were loaded onto nitrogen-doped carbon (NDC) prepared under the primitive Earth's atmospheric conditions. These metal-loaded NDC samples were found to catalyze both WOR and ORR under light illumination. The chemical pathways initiated by the pristine and metal-loaded NDC were investigated. This study provides valuable insights into potential mechanisms relevant to the early evolution of our planet.