Wenbao Huang, Houfen Li, Zhiyi Dang, Shibo Xu, Rong Han, Rui Li, Aijuan Zhou, Xiuping Yue, Xu Zhao, Jiancheng Wang
Persulfate-assisted visible-light photocatalysis shows promise for refractory organic pollutant degradation but is limited by low charge separation/utilization in conventional catalysts. Leveraging the unique charge-separation capability of Schottky junctions and the tunable surface charge properties of ferroelectric materials, this study innovatively constructs a polarized BiFeO3-Ag (BFOA*) Schottky junction catalyst to drive the synergistic persulfate (PS)/visible-light (VIS) catalytic degradation of quinoline. Comprehensive characterization confirms the formation of the BiFeO3-Ag Schottky junction. Pronounced hysteresis loops and distinct domain structures observed via piezo-response force microscopy (PFM) demonstrate that corona poling induces a stable built-in ferroelectric polarization field. In the VIS/PS/BFOA* system, the polarized catalyst achieves 98.8 ± 1.1% quinoline degradation within 90 min, significantly outperforming its unpolarized counterpart (88.1 ± 4.0%), while maintaining excellent cycling stability and markedly reduced effluent toxicity. Mechanistic investigations and DFT calculations reveal that ferroelectric polarization facilitates directional electron migration through the Schottky junction, while the Schottky barrier suppresses the backflow of the photogenerated electrons, thereby synergistically improving charge carrier separation. Simultaneously, ferroelectric polarization-induced charged surface sites promote the adsorption and activation of PS. This dual function results in abundant reactive species (h+, ·O2-, SO4·-, ·OH), which are responsible for the efficient quinoline degradation. This work highlights ferroelectric polarization engineering as a pivotal strategy for strengthening Schottky junction catalysts and establishes it a viable approach for designing sustainable advanced oxidation processes in wastewater treatment.