Activating graphitic carbon via a core/shell WO3/carbon architecture for electrocatalytic deactivation of dilute antibiotics

Electrocatalytic hydrodechlorination (EHDC) is an effective technology for the deactivation of antibiotics in environmental matrices. Although carbon-based catalysts exhibit good durability in EHDC, their catalytic performance is limited by suboptimal electronic structures. In this study, a core/shell catalyst consisting of a defective tungsten oxide core and a graphitic carbon shell (WO 3 @GP) was fabricated to enhance the catalytic activity of carbon materials in EHDC. WO 3 @GP achieved a mass activity of 80 g FLO h −1  g −1 (533 g FLO h −1  m −2 ) and a florfenicol (FLO) removal efficiency of 99.6 % in treating 20 mg L −1 of FLO at −1.3 V vs. Ag/AgCl, outperforming single carbon black, WO 3 , and previously reported carbon-based catalysts. Mechanistic studies revealed that the oxygen defects in WO 3 facilitated interfacial electron transfer from the core to GP shell, elevating the Fermi level of the GP shell from −4.18 eV (pristine GP) to −3.89 eV. This upward shift reduced the energy gap toward the lowest unoccupied molecular orbital (LUMO, −2.57 eV) of the C Cl bond in FLO, improving electronic orbital alignment and accelerating electron transfer for enhanced EHDC. Moreover, WO 3 @GP effectively suppressed FLO resistance gene expression in swine wastewater, reducing its relative abundance from 48.2 to 0.96. This study demonstrated that defective metal oxide core-supported carbon shell represents a viable strategy for activating carbon-based catalytic systems.