Eliminating Thiamphenicol with abundant H* and •OH generated on a morphologically transformed Co3O4 cathode in electric field

Abstract

Degradation of halogenated organic compounds using the electro-reduction process is a promising approach for advanced water treatment. In this work, antiferromagnetic Co3O4 nanoparticles were first loaded on a uniform anodic porous TiO2 surface through a hydrothermal strategy, then subjected to an electrochemical reduction, which transform from nanoparticle-shape to interconnected nanoflakes. Compared with the pristine Co3O4 nanoparticles, the morphologically transformed Co3O4 cathode features a porous interface with amorphous Co(OH)2 and CoOOH shell, which favors the generation of abundant •OH radicals along with lower overpotential for reducing H+ to H*. On account of the plentiful radicals and self-supporting nature, the resulting Co3O4 cathode retains high activity for efficiently degrading Thiamphenicol in water, even after 10 h run, demonstrating remarkable durability. Moreover, it is adaptable in a wide pH window of 3 to 10, and effectual when the initial Thiamphenicol concentration increases from 0.5 to 50 mg/L regardless of the water background (tap water, lake water, or river water). This study delivers a profound cognition about the dynamic behaviors of Co3O4-based electrocatalysts applied in eliminating halogenated antibiotics.