Constructing an orderly electron transport channel on boron regulated biomass carbon fiber for selective ROS...

Antibiotic pollution has raised widely attention due to the difficult biodegradation and lasting toxicity to public health, metal-free material based heterogeneous catalysis is a highly-promise and eco-friendly technology for organics elimination. Herein, boron doped biomass carbon fiber (B-CF) was synthesized to construct orderly electron transport channels for enhancing catalytic performance and deeply purifying organics polluted water. Integrating systematical quenching experiments and EPR detection, O₂^·- and ¹O₂ are found to be dominating reactive oxygen species (ROS) for norfloxacin (NOR) degradation rather than ∙OH or SO₄^∙-. Adsorption, catalytic degradation in pristine CF/peroxodisulfate (PDS) and B-CF/PDS systems, electrochemical tests, and theory calculations were compared and the results suggested B-CF surface can trigger intense electron transfer via simultaneous activating NOR and PDS, and electrons transferred from NOR to B-CF-PDS compound, resulting in selective and remarkably enhanced ROS generation. Moreover, it was found that B-CF exhibited surprising adsorption capacity for NOR (834.4 mg g^-1), and it can also remove SO₄^2- from the solution through electrostatic attraction. This B-CF/PDS system is efficient within a wide operation pH from 3 to 11 and exhibits long lasting activity (> 274 h maintaining over 80% efficiency). This study unveils the highly selective formation of O₂^-· and ¹O₂ and solves the short lifetime of catalysts in persulfate-based catalysis, which provides feasible technology for advanced water purification.