Construction of a La-ZnIn2S4/MIL-125(Ti) heterojunction for highly efficient photocatalytic degradation of aflatoxin B1

Abstract

Nowadays, aflatoxin B₁ (AFB₁) contamination is considered as one of the most common food safety issues for humans and animals. As one of the most advanced oxidation techniques, photocatalytic degradation can break down organic contaminants into nontoxic and harmless materials efficiently. In this paper, we explored the degradation efficiency of AFB₁ by ZnIn₂S₄. To promote the photocatalytic degradation efficiency of AFB₁, ZnIn₂S₄ was coupled with MIL-125(Ti) and then doped with La [this hybrid is denoted as La-ZnIn₂S₄/MIL-125(Ti)] to effectively convert it via photocatalytic generation of superoxide radicals (˙O₂⁻ and ˙OH) and achieve much enhanced photocatalytic performance, which is demonstrated by degrading 97.6% of AFB₁. According to the transient photocurrent responses, the doping of La and coupling with MIL-125(Ti) can highly improve the efficient separation of the photoinduced electron–hole pairs on ZnIn₂S₄, leading to the effective conversion of OH⁻ and O₂ into ˙O₂⁻ and ˙OH, respectively, during the photodegradation process. This strategy of coupling with MOFs and doping with rare earth elements provides a facile and efficient method for degrading food pollutants produced by aflatoxins.