Interfacial electric-field-regulated Bi₂MoO₆/BaTiO₃ piezoelectric heterojunction for enhanced sulfamethoxazole...

Sulfamethoxazole (SMX), an emerging contaminant frequently detected in water, poses a risk to drinking water safety and ecosystem health. Piezoelectric catalysis offers a light- and oxidant-free approach to contaminant removal, but its application is limited by rapid charge recombination and insufficient understanding of interfacial charge dynamics. Here, we construct a Bi₂MoO₆/BaTiO₃ (BMO/BTO) heterojunction that leverages an interfacial electric field induced by the work function difference to enhance charge separation under ultrasonic stimulation. The optimized catalyst exhibits efficient and competitive piezocatalytic performance under the present reaction conditions, achieving a 97.74% removal rate of SMX within 60 min. It maintains stable activity over six cycles and demonstrates excellent degradation capabilities for various emerging pollutants (including tetracycline, bisphenol A, 1-naphthol, and acetaminophen). Radical trapping and EPR confirm ·O₂^- and ·OH as the primary reactive species. By integrating experiments, DFT calculations and transformation pathway analysis, we reveal that the interfacial electric field promotes charge redistribution, suppresses carrier recombination, and drives SMX transformation. Combined with the results of software simulation predictions and toxicity tests on Escherichia coli and Chlorella, these findings further indicate that the overall toxicity of treated SMX has been reduced compared to untreated SMX. This study designed a piezoelectric heterojunction material for pollutant degradation, with the aim of achieving efficient degradation and toxicity reduction of emerging pollutants.