Efficient Photocatalytic Activation of Peroxymonosulfate by Cobalt-Doped Oxygen-Vacancies-Rich BiVO₄ for Rapid Tetracycline Degradation

Abstract

In this work, cobalt-doped oxygen-vacancies-rich BiVO 4 (Co/BiVO 4 -V o ) was successfully synthesized for the degradation of tetracycline (TC) by activated peroxymonosulfate (PMS) under visible light. The morphologies, microstructures, and optical properties of the photocatalysts were analyzed in detail. Co/BiVO 4 -V o exhibited significantly enhanced degradation, removing 92.3% of TC within 10 min, which was greater than those of pure BiVO 4 (62.2%) and oxygenvacancies-rich BiVO 4 (BiVO 4 -V o ) (72.0%), respectively. The photogenerated charge separation and transport properties were explored through surface photovoltage (SPV), photoluminescence spectrum (PL), and UV−vis diffuse reflectance spectroscopy (UV−vis DRS) measurements. Additionally, an in-depth investigation was conducted on the photocatalytically assisted advanced oxidation processes based on SO 4•− (SR-AOPs) for the degradation of organic pollutants. The experimental results showed that the introduction of oxygen vacancies and Co doping achieved an effective separation of photogenerated carriers, which could accelerate the cycling between Co 3+ and Co 2+ and further activate PMS. The results of free radical capture experiments and electron spin resonance (ESR) experiments showed that reactive oxygen species (ROSs) such as 1 O 2 , •O 2 − , and SO 4•− played a dominant role in the removal of pollutants. This work provides a novel insight into the further development of efficient and rapid PMS photoactivators for environmental remediation of water bodies.