Heterogeneous activation of peroxygens by iron-based bimetallic nanostructures for the efficient remediation of contaminated water. A review

Heterogeneous advanced oxidation processes (AOPs) catalyzed by iron-based bimetallic nanoparticles were discovered efficient for water remediation due to the formation of a variety of reactive species, such as sulfate radical, hydroxyl radical, superoxide radical, and nonradical oxidation routes. The addition of reducing agents or the incorporation of a second metal accelerated the Fe (III)/Fe (II) redox cycle, allowing for the in-situ formation of H2O2 (a precursor to center dot OH). The activated peroxymonosulfate (PMS) system oxidized contaminants faster than the activated peroxydisulfate (PS) and H2O2 systems. Besides, iron-based bimetallic catalysts demonstrated potent antimicrobial activity and toxic heavy metals removal from contaminated water. This review summarizes the recent advances in synthesis methods, activation of peroxygens, and degradation mechanisms via bimetallic iron, iron-based bimetallic oxide, iron-based metal-organic frameworks, chalcopyrite, and iron-based perovskites. Additionally, the effects of various water constituents and parameters (stoichiometric ratio, catalyst concentration, oxidant dosage, pH, anions, and natural organic matter) are discussed. It is anticipated to broaden our understanding of the activation mechanisms, removal efficiency, and stability of iron-based catalysts and transformation pathways.

Automated summary

Heterogeneous advanced oxidation processes (AOPs) catalyzed by iron-based bimetallic nanoparticles have been found to be efficient for water remediation, producing a variety of reactive species to remove contaminants. Iron-based catalysts also demonstrate antimicrobial activity and can remove toxic heavy metals. This review summarizes recent advances in synthesis methods, activation mechanisms, and the effects of various factors on the performance of iron-based catalysts.