Utilizing Macroscopic Polarization for Effective Fe<sup>3+</sup>/Fe<sup>2+</sup> Cycling and H<sub>2</sub>O<sub>2</sub> Activation in Fenton-like Aniline Aerofloat Degradation
Shuchen Tu, Tianyang Hao, Xiangming Li, Tao Chen, Yaqing Wang, Junhao Zhang, Chengyu Zhou, Linghui Kuang, Peng Xu, Yuan Zeng, Keqing Ouyang, Shaojun Jiang, Bo Yan
Abstract
The great ecological hazards of mineral processing wastewater containing aniline aerofloat dictate the need to implement thorough mineralization degradation, such as Fenton-like catalysis. To address the low efficiency of H 2 O 2 conversion and the short reactive duration in Fenton-like aniline aerofloat degradation, in this study, we demonstrated a novel piezo-enhanced mechanism that utilizes piezo-induced macroscopic polarization to significantly enhance H 2 O 2 conversion and Fe 3+ /Fe 2+ cycling in the Fe 3 O 4 –Bi 4 Ti 3 O 12 heterojunction. The reaction activity was increased 2-fold, resulting in the removal of almost 85% of aniline aerofloat within 40 min at a pH of 4–10. The combination of piezoelectric force microscopy, in situ electrochemical measurement, transmission electron microscopy, and X-ray photoelectron spectroscopy demonstrated that Fe 3 O 4 –Bi 4 Ti 3 O 12 exhibited a strong piezo-response and improved charge migration when exposed to a piezo-potential. The piezo-induced large-scale charge transfer facilitated the adsorption of H 2 O 2 and released the kinetic constraints for Fe 3+ /Fe 2+ cycling by inducing charge enrichment, as confirmed by radical monitoring, photoluminescence spectroscopy, and theory calculations. Consequently, the optimization of the aforementioned key processes enhances the yield rate (1.363 μmol min –1 ), selectivity of HO • conversion (18.88%) by H 2 O 2, and the reaction’s persistence. This work presents an innovative concept to enhance the performance and endurance of Fenton-like reactions. It also provided an understanding of the advanced oxidation process treatment of mineral processing wastewater.