Designing an iron-doped basic magnesium sulfate photocatalyst for wide spectral photoresponse and superior catalytic activity

Abstract

This study explored a self-supporting iron-doped basic magnesium sulfate (Fe-BMS) photocatalyst with a wide spectral response. Fe doping reduced the bandgap of BMS from 5.6 eV to 3.8 eV through replacing some magnesium ions within the BMS lattice, thereby extending the light response range from the ultraviolet to the visible light range, and enhancing the adsorption of water molecules or hydroxyl groups to promote the generation of hydroxyl radicals. Under simulated sunlight, the photocatalytic degradation efficiency of Fe-BMS for methyl orange, phenol, ciprofloxacin, octadecylamine, and 4-dodecylmorpholine all exceeded 96%. Furthermore, Fe-BMS directly undergoes solid-phase photodegradation after adsorbing saturated 4-dodecylmorpholine to mitigate secondary pollution caused by intermediate products in aquatic systems during degradation, and achieves a degradation efficiency three times greater than that of BMS. This study not only developed a novel magnesium-based gel photocatalyst with a wide spectral response but also provided innovative ideas and practical methods for the removal of environmental organic pollutants.