Efficient piezoelectric catalytic degradation of organic pollutants by BTO@PANI via ultrasonic enhancement and energy-saving aeration

Piezoelectric catalysis has emerged as a sustainable technology for pollutant degradation, with barium titanate (BTO) serving as a prominent lead-free piezoelectric material. However, its practical application remains constrained by limited degradation efficiency. To address these challenges, polyaniline-incorporated BTO nanocomposites (BTO@PANI) were synthesized via in-situ polymerization to enhance piezoelectric polarization and catalytic performance. The composites were evaluated for degrading dyes and pharmaceuticals under both ultrasonic and aeration-driven conditions, with systematic investigation of influencing factors including pH, catalyst dosage, aeration rate, and bubble size. The optimized BTO@PANI 0.2 composite exhibited exceptional catalytic activity, achieving a 57 % enhancement in degradation efficiency and a reaction rate constant (k = 0.0218 min⁻¹) 15.7 times greater than pure BTO under ultrasonic excitation. The aeration-driven process used only 23.3 % of the energy that ultrasonication did, which is very impressive. The composite maintained excellent stability through four consecutive degradation cycles under both excitation modes. The catalytic mechanism was systematically investigated through radical trapping experiments, electron paramagnetic resonance (EPR) analysis, and comprehensive material characterization (XRD, SEM, FTIR, XPS, EIS). This work provides new idea for designing efficient piezoelectric catalysts and demonstrates a promising energy-saving strategy for advanced oxidation processes in water treatment.