Promoting Surface Reconstruction of Low-Cost Stainless Steel Catalyst for Efficient Oxygen Evolution Reaction

The development of cost-effective transition metal catalysts for oxygen evolution reaction (OER) is critical for the production of hydrogen fuel from water splitting. Low-cost and efficient stainless steel-based catalysts are expected to replace the scarce platinum group metals for large-scale energy applications. Here in this work, we report the conversion of commonly available inexpensive and easily accessible 434-L stainless steel (SS) into highly active and stable electrodes by corrosion and sulfuration strategies. The Ni_xFe_1−xS layer as a pre-catalyst and S-doped Ni_xFe oxyhydroxides in situ formed on the catalyst surface are the true active species for OER. The optimized 434-L stainless steel-based electrocatalyst exhibits a low overpotential of 298 mV at 10 mA cm⁻² in 1.0 M KOH with a small OER kinetics (the Tafel slope of 54.8 mV dec⁻¹) and good stability. This work reveals the 434-L alloy stainless steel with Fe and Cr as the main elements can be used as qualified OER catalysts by surface modification, along with a new mentality to solve the energy and resource waste problems.