Solid-state grinding synthesis of highly dispersed iron oxide on the silica hollow spheres and its applications in Fenton-type catalysis

Abstract

Achieving high catalytic activity in supported metal catalysts depends on maximizing the number of exposed active sites. This study presents a simple yet effective strategy for anchoring highly dispersed iron oxide onto silica hollow spheres (HMSS) to optimize active site exposure. Via a solid-state grinding process, iron salts were incorporated into the as-synthesized HMSS while retaining the template. Subsequent calcination simultaneously decomposed the iron precursor and the template, resulting in well-dispersed iron oxides on the HMSS (FeO_x–HMSS). The catalytic performance of FeO_x–HMSS was evaluated in Fenton-like oxidation of tetracycline (TC) and rhodamine B (RhB). Results demonstrated that FeO_x–HMSS outperformed mechanically mixed Fe₂O₃/HMSS and Fe₃O₄/HMSS samples in degrading both pollutants, underscoring the superiority of the solid-state grinding method for FeO_x–HMSS synthesis.