Barium titanate@covalent organic framework core–shell nanoparticles for adsorption-enhanced piezo-photocatalysis

Both large adsorption capacity and high catalytic activity play a key role in water purification via effective degradation of organic pollutants. Herein, a well-defined core–shell heterostructure (BTO@TD-COF) was fabricated by polycondensation of 1,3,5-tris(4-aminophenyl)benzene and 2,5-dimethoxyterephaldehyde on barium titanate (BTO) for effective adsorption that is followed by the piezo-photocatalytic degradation of bisphenol A in water. Under simultaneous ultrasound and visible-light irradiation, the separation of carriers is boosted by the built-in electric field generated in BTO, which endows BTO@TD-COF with outstanding piezo-photocatalytic activity. With the advantages of favorable catalytic and adsorption performance, Bisphenol A (5 ppm, 1000 mL) can be completely degraded within 75 min by BTO-3@TD-COF (25 mg), and the degradation rate is 31.9 and 2.5 times that of BTO and TD-COF, respectively. It provides an efficient strategy for cleaning of organic wastewater by piezo-photocatalysts combined with excellent adsorption capacity.