Evaluation of the piezoelectric effects of BaTiO3 for methyl orange photodegradation performance in slurry mode and immobilized PVDF membrane

Removal of harmful contaminants from wastewater is a global issue handled by various methods. Photocatalysis, an emerging, environmentally friendly wastewater treatment method using semiconductor materials, is effective but needs to be improved for better outcomes. Piezoelectric catalysis can enhance contaminant photodegradation. Piezoelectric BaTiO3 (BTO) is an excellent photocatalyst for the removal of organic contaminants, enhanced by external stress that generates spontaneous polarization. This study demonstrates improved piezo-photocatalytic degradation rates for tetragonal BTO nanoparticles with piezoelectric characteristics, synthesized hydrothermally. The materials’ piezocatalyst features, such as non-centrosymmetric tetragonal crystallization, slit-shaped mesoporous morphology, Ti–O lattice vibration, broad emission band, thermal stability, and 13.76 m2/g effective surface area, were confirmed through multiple advanced characterization techniques. Ultrasonic waves were used to test BTO piezoelectric properties in a slurry photoreactor and a stationary flat-sheet BTO-PVDF composite membrane to determine methyl orange (MO) piezo-photocatalytic degradation efficiency. The photoactivity of the material was evaluated by measuring the photodegradation efficiency of MO under visible light (300 W, λ ≥ 445 nm) irradiation. Using a UV–Vis spectrophotometer, MO absorbance was measured to determine BTO degradation performance in the slurry and the membrane with or without ultrasonic stress induction. After 120 min in visible light, MO degraded 62.7% in slurry mode without external stimulation and 89.5% with sonication. The flat-sheet membrane BTO photodegraded 49.2% without stress induction and 77% with sonication. BTO degrades 89.5% in slurry mode due to light-exposed surface area and piezoelectric polarization effects. This study provides fundamental knowledge of piezoelectric materials and their efficient use of photocatalytic and piezoelectric effects to develop piezoelectric-assisted photocatalysis.