Oxygen-vacancy-rich Co3O4/g-C3N4 enables highly efficient electrocatalytic dehalogenation in a flow-through reactor

Electrocatalytic dehalogenation provides an efficient and sustainable strategy for cleaving carbon-halogen bonds, yet its practical efficiency is often limited by insufficient catalytic activity alongside inherent mass transfer constraints. To address this challenge, this study focused on both the catalyst and reactor levels. Herein, a non-noble metal catalyst, oxygen vacancy-rich Co 3 O 4 /g-C 3 N 4 (O v -CoCN), was developed and integrated into a flow-through reactor for efficient electrocatalytic reductive dehalogenation, which significantly enhanced mass transfer and reaction kinetics. Using the halogenated antibiotic thiamphenicol (TAP) as the target pollutant, the system demonstrated outstanding degradation efficiency under continuous-flow operation. Under optimal conditions with a catalyst loading of 7.1 mg/cm 2 , pH 5, a flow rate of 2 mL/min, and a current density of 7 mA/cm 2 , nearly complete removal of 10 mg/L TAP was achieved. The introduced oxygen vacancies, engineered to modulate the electronic structure of CoCN, played a critical role in facilitating electron transfer and promoting the generation of the key reactive species, atomic hydrogen (H*). The catalyst exhibited excellent application potential, maintaining high removal efficiency across a broad pH range (3−11) and pollutant concentrations (1–50 mg/L), and showed remarkable stability over a 12-h continuous operation. This work provides new insights into the design of both reactors and catalysts for efficient electrocatalytic dechlorination.