In-situ synthesis of sepiolite-supported ceria nanocrystal composites for efficient removal of aflatoxin B1: Enhanced degradation of mycotoxins in the environment by sepiolite nanofibers

Abstract

Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins, which has a serious effect on animals and human health and causes secondary pollution in the environment. Herein, the in-situ synthesis of ceria nanocrystals on sepiolite nanofibers successfully improved photocatalytic efficiency for the removal of AFB1 in aqueous solution under visible light. The optimum removal efficiency of the CeO2/sepiolite (Ce/Sep) composites was up to 93.3% within 3 h and was nearly 2.7 times higher than that of nano ceria. After a series of characterization, it was indicated that the significantly enhanced removal performance of Ce/Sep composites can be attributed to the large specific surface of sepiolite, leading to the homogeneous distribution of ceria and reducing their particle sizes to 5–20 nm, which increased the reaction active sites. Besides, sepiolite as an electron acceptor also inhibited the photogenerated electron-hole pairs recombine, while the interface effect and function group reaction between sepiolite and ceria extended absorption in the visible light region and effectively improved the separation efficiency of photogenerated electron-hole pairs, which produced more reactive oxygen species to destroy the structure of AFB1. This work demonstrates that the Ce/Sep composites possess excellent photocatalytic activity and have great application prospects in the treatment of AFB1 environmental pollution.