Unraveling the role of V modified CoO in a wide pH range Fenton-like process.

Abstract

Building an effective heterogeneous Fenton catalyst over a broad pH range without the requirement for external energy input is still challenging. Herein, a vanadium-cobalt bimetallic catalyst (Co-V-8) are employed to extended a pH range of 3-9 by activating H₂O₂ as a Fenton-like catalyst. The Co-based Co-V-8 catalysts demonstrate high diclofenac sodium deterioration efficiency (98.2%) under both acidic and alkaline environments, and the kinetic reaction rate within 15 min could reach 0.288 min^-1. Crucially, density functional theory (DFT) calculations imply that the Co-V-8 owned a narrower band gap and a higher Fermi level, which beneficial for quickening the electron transfer process. Results showed that the catalyst modified by V could introduce abundant oxygen vacancies, promote the decomposition of H₂O₂ via V³⁺ and V⁴⁺, and enhance the conversion of Co³⁺ and Co²⁺, accelerating the formation of ·OH, ·OOH, ·O^-₂ and electron transfer process. Additionally, Co-V-8 promoted the utilization rate of H₂O₂ exceeding 90% and exhibited exceptional catalytic ability in cleaning actual pharmaceutical wastewater. This research offers a sustainable separable and purification technology for wastewater remediation.