Enhanced oxygen bubble detachment from electrolytic iron anode by regulated micro-nano structures

This study addresses the issue of increased energy consumption caused by bubble adhesion during the oxygen evolution reaction in electrochemical ironmaking anodes. By constructing a femtosecond laser-processed micro-nano porous array structure on the anode surface, rapid and spontaneous bubble detachment was achieved. The wetting characteristics, bubble behavior, and electrochemical performance of electrodes with different structures were systematically investigated. Results show that a microporous array with a pore size of 50 μm optimally balances bubble nucleation density, detachment behavior, and active surface coverage. The electrode achieves an OER potential of 1.24 V at 50 mA·cm^-2, which is 9% (120 mV) lower than that of conventional dimensionally stable anodes, along with shorter bubble detachment time and excellent potential stability. Furthermore, multiphysics modeling confirms that the beneficial micro-convection generated during periodic bubble detachment enhances the limiting current density of mass transfer. This work provides new insights and a theoretical foundation for the development of efficient, low-energy green electrochemical ironmaking technologies.