Visible-light photoelectrocatalysis/HO synergistic degradation of organic pollutants by a magnetic FeO@SiO@mesoporous TiO catalyst-loaded photoelectrode.

In this paper, we describe a method for photoelectrocatalysis (PEC)/HO synergistic degradation of organic pollutants with a magnetic FeO@SiO@mesoporous TiO (FST) photocatalyst-loaded electrode. At optimal conditions of pH 3.0, 2.25% HO, working electrode (fixed FST 30 mg) potential +0.6 V ( SCE), and 10 mg L of all experimental pollutants, the FST PEC/HO synergistic system exhibited high activity and stability for the removal of various organic pollutants under visible light with comparable degradation efficiencies, including MB (98.8%), rhodamine B (Rh B, 96.7%), methyl orange (MO, 97.7%), amoxicillin (AMX, 83.9%). Moreover, this system obtained TOC removal ratios of 83.5% (MB), 77.9% (Rh B), 80.2% (MO), 65.5% (AMX) within 8 min. The kinetic rate constants of the PEC/HO synergistic system were nearly 53 and 1436 times higher than that of the PEC process and HO photolysis under visible light, respectively. Furthermore, the main reactive oxidant species (˙OH, ˙O ) were studied and enhanced mechanisms of the photocatalytic-electro-HO coupling system were proposed. This work brings new insights to efficiently purify organic pollutants by PEC coupled with peroxide under solar light illumination.