Phase change on stainless-steel mesh for promoting sulfate radical formation via peroxymonosulfate oxidation

Abstract

Surface-etched and N₂-annealed stainless-steel mesh (NESS) was fabricated by a chemical etching and annealing treatment under a nitrogen atmosphere of a cheap stainless-steel mesh, and employed to degrade organic pollutants via peroxymonosulfate (PMS) activation. Extensive characterization showed that surface modification could bring about phase change and metal layer generation with a thickness of several nanometers. Excellent electron conductivity and the favorable morphology with coexisting Fe, Ni, and Cr species in NESS make an effective electron transfer between catalysts and PMS. The as-prepared NESS itself can induce the PMS activation, and oxygen vacancies can strengthen chemical bonding with PMS, providing active sites to activate PMS. As a result, NESS possessed a superior activity in PMS activation for mineralization of organic compounds. Electron paramagnetic resonance and quenching experiments demonstrated − SO₄•⁻ , HO•, − O₂•⁻ and ¹O₂ were the dominant reactive species. Considering the procedure simplicity, NESS is an effective and low-cost catalyst for environmental applications.