Bridge–Gel Co-Path reactor couples interfacial polarization with substrate enrichment for piezocatalytic treatment of polystyrene nanoplastics

Bridge–Gel Co-Path reactor couples polarization with nanoplastic enrichment. • Ti–O–P–O–Zr bridges enhance interfacial piezoresponse to ~145 pm V −1 . • Hydrogel enrichment gives a PS NPs adsorption capacity of 312.4 mg g −1 . • UTPCH achieves 68.4% apparent PS NPs removal without light or oxidants. • Reactor-level design improves charge use and substrate delivery. Piezocatalytic treatment of polystyrene nanoplastics (PS NPs) is limited by inefficient conversion of mechanical input into interfacial charge and by poor delivery of dilute particles to reactive sites. Here, we constructed a Bridge–Gel Co-Path (BGCP) reactor that coupled a Ti-O-P-O-Zr-bridged UiO-66-NH 2 /C,N-TiO 2 heterointerface with a polyethyleneimine-modified cellulose nanofibril hydrogel. The phosphate-mediated covalent–ionic bridge integrated the two components into a strongly coupled heterointerface with enhanced interfacial polarization and charge redistribution. Bader charge analysis indicated pronounced interfacial charge redistribution around the phosphate bridge, with ca. 1.20 |e| localized in the bridged region, while piezoresponse force microscopy yielded an apparent local piezoresponse coefficient (d 33 , eff ) of ca. 145 pm  V −1 . The hydrogel network provided both strain relay and substrate enrichment, with a Langmuir maximum adsorption capacity of 312.4 mg g −1 toward PS NPs. Under 40 kHz ultrasonic excitation, the BGCP reactor achieved 68.4% overall apparent removal of PS NPs after 75 min of adsorption pre-equilibration followed by 105 min of mechanical excitation, retained 87.6% of its initial activity after ten cycles, and kept the individual leached concentrations of Ti, P, and Zr below 10 ppb in the effluents collected during cycling. Calorimetry-derived apparent energy metrics were provided to contextualize the energy scale of the present laboratory configuration. These results established the integration of a bridged polarization interface with a transport-active hydrogel network as an effective reactor-design strategy for intensifying mechanically driven interfacial oxidation of dilute colloidal pollutants. Download: Download high-res image (183KB) Download: Download full-size image