Synthesis of Bi<sub>25</sub>FeO<sub>40</sub> Nanoparticles with Oxygen Vacancies via Ball Milling for Fenton Oxidation of Tetracycline Hydrochloride and Reduction of Cr(VI)
Wenjuan Zou, Jintao Dong, Mengxia Ji, Bin Wang, Yingjie Li, Sheng Yin, Huaming Li, Jiexiang Xia
Abstract
Though heterogeneous Fenton-like reactions possess various characteristics such as a wide application range and mild reaction conditions, their reactivity is currently restricted by unsatisfactory H 2 O 2 decomposition efficiency and low pH adaptation. Hence, Bi 25 FeO 40 nanoparticles prepared via the mechanical ball-milling method (Bi 25 FeO 40 -B) with extensive oxygen vacancies possess high reactive oxygen species production performance by enhancing the H 2 O 2 decomposition for tetracycline hydrochloride oxidation and Cr(VI) reduction. H 2 O 2 decomposition efficiency can reach 55.3% in the presence of the Bi 25 FeO 40 -B catalyst, which is much higher than that of Bi 25 FeO 40 prepared by the traditional hydrothermal method (23.8%). The Bi 25 FeO 40 -B/H 2 O 2 heterogeneous Fenton system demonstrates efficient performance for simultaneous oxidation of tetracycline hydrochloride (TCH) and reduction of Cr(VI). It is capable of removing 75.2% of 50 mg/L TCH and 93.0% of 20 mg/L Cr(VI) at pH initial = 7, respectively. Abundant oxygen vacancies on the surface of Bi 25 FeO 40 -B nanoparticles due to the nanometer size effect can accelerate the decomposition of H 2 O 2 to promote the formation of reactive oxygen species for removing the target organic pollutants and reduction of Cr(VI). Consequently, this work provides a strategy for the preparation of oxygen-rich Bi 25 FeO 40 catalysts for efficient degradation of contaminants and depicts the bright future of Fe-based metal oxides with oxygen vacancies on H 2 O 2 activation in Fenton-like reactions.