Enhanced activation of molecular oxygen for efficient chloroquine phosphate degradation with CuO@Co3O4/GF heterostructure: Promoting mechanisms of oxygen vacancy and interfacial electronic engineering

Abstract

To address the issue of insufficient oxygen activation by electrode materials in electro-Fenton-like technology, we prepared a novel composite by one-step electrodeposition on graphite felt (GF) followed by calcination. The CuO@Co₃O₄/GF composite possessed oxygen vacancies and a heterostructure, which effectively modulated the catalyst’s charge distribution, facilitating oxygen adsorption and activation. The heterostructure enhanced the interfacial electron transfer between CuO and Co₃O₄, shifting the Co d-band center to higher energies and increasing its electron density, which reduced the oxygen adsorption energy barrier. The presence of oxygen vacancies reduced the kinetic barriers of the oxygen reduction reaction and provided additional active sites. CuO@Co₃O₄/GF was utilized for chloroquine phosphate degradation, achieving 100 % removal within 60 min, with a reaction rate 5.6 times higher than that of GF, and exhibited exceptional stability and applicability over a broad pH range. This study presents a facile approach for preparing composites with both oxygen vacancies and heterostructures, providing new insights into enhancing electrocatalytic performance.