Preparation of metal-organic framework from in situ self-sacrificial stainless-steel matrix for efficient water oxidation

The oxygen evolution reaction (OER) on the anode is one of the key half-cell reactions in water electrolysis and metal-air batteries, and its reaction process is mainly hampered by sluggish kinetics and low efficiency. In this work, a series of MIL-53 metal-organic framework (MOF) derived materials grown on self-sacrificial SSM substrate was designed and synthesized for efficient water oxidation in alkaline solutions. The as-obtained FeNiBDC/SSM (SSM = stainless steel matrix and H₂BDC = benzene-1,4-dicarboxylic acid) with MIL-53 MOF of uniform morphology and high porosity was successfully synthesized via a facile one-step method using recycled stainless steel as a template. Afterward, FeNiBDC/SSM was accompanied by morphological and structural changes during the OER process while the modified MOF components on the SSM substrate degraded into Fe/NiOOH species, which serve as catalytic centers. After the stability test for 100 h, the used optimal FeNiBDC/SSM2 exhibited a promising electrocatalytic OER performance with a low Tafel slope of 74.5 mV dec^-1, a small overpotential of 239 mV at 10 mA cm^-2, and high current retention of 95.20 %. This work provides a new research idea for the sustainable recycling of existing resources and the one-step in-situ preparation of MOF/substrate electrocatalyst for OER.