Synergistic Effects of MHD Dynamics and Oxygen Vacancies on Electrode Polarization in Photoelectrocatalysis CO ₂ Reduction Systems

ABSTRACT Photoelectrocatalysis reduction of CO 2 into products such as CO and CH 4 is an effective strategy for improving carbon utilization and advancing the development of renewable energy. Improving the catalytic efficiency by regulating the polarization behavior of the electrode has been proven to be an effective method. In this study, a method for preparing a Ti:Fe 2 O 3 /CuFeO 2 ‐v photoanode with oxygen vacancies and heterojunctions for PEC CO 2 reduction is reported. Oxygen vacancies not only enhance the carrier transport ability of the electrode and improve the resistance polarization, but also regulate the material's magnetic properties. Based on this, we utilize the magnetic fluid dynamics (MHD) effect to reduce the thickness of the diffusion layer on the electrode surface, thereby improving mass transfer and solving the concentration polarization problem. This adjustment increased the current density to 1.49 mA cm −2 and increased the CO yield to 154.27 mL h −1 . This method innovatively applies the MHD insights of the electrochemical oxygen evolution reaction (OER) to photoelectrochemical CO 2 reduction, aiming to optimize the electrode reaction kinetics for efficient CO 2 conversion, marking a significant progress in the field of photocatalytic CO 2 reduction.