Dual light-driven p-ZnFe2O4/n-TiO2 catalyst: Benzene-breaking reaction for malachite green

Heterocyclic aromatic compounds such as malachite green can cause immense harm to the environment and mankind because of their toxic bio-accumulation and insufficient biodegradation. ZnFe 2 O 4 /TiO 2 (ZF-T) has attracted attentions as a visible-light-driven catalyst because it can break and mineralize benzene through photolysis. Compared with TiO 2 , which photodegrades only 53.5% malachite green, anatase TiO 2 loaded with ZnFe 2 O 4 has greater photocatalytic activity and can degrade up to 90.1% malachite green. Furthermore, a photocatalytic efficiency above 80% can be obtained through five consecutive cycles with a duration of 4 h. In this study, ZF-T was characterized, and its photolytic parameters, including dosage, pH, time, and ionic strength, were optimized. The photolytic products of malachite green were analyzed by ultraviolet–visible spectroscopy and liquid chromatography-mass spectrometry, which confirmed that ZF-T can drive visible light to produce •O 2 − and H + free radicals that can efficiently degrade heterocyclic aromatic hydrocarbons and cleave benzene rings. These outcomes deepen our understanding of the development and applications of visible-light-driven ZF-T composites in the field of wastewater purification.