Amorphous CoSx in heterogeneous electro-Fenton: A 1O2-mediated system for efficient and selective water decontamination

Abstract

Heterogeneous electro-Fenton (hetero-EF) technology represents a promising and safe approach to water treatment. However, conventional hetero-EF catalysts still face the challenges of removing contaminants selectively and operating efficient in complex water quality. We proposed a novel system utilizing amorphous CoSx (A-CoSx) that overcame these limitations. This material generated only singlet oxygen (1O2), a highly specific oxidant, for contaminants degradation. Unlike traditional crystalline catalysts, A-CoSx efficiently utilized hydrogen peroxide (H2O2) to directly produce 1O2, exhibiting high catalytic activity across a wide pH range (3.0–11.0). The formation mechanism of 1O2 was confirmed through experimental investigations, density functional theory (DFT) calculations, and advanced characterization techniques. This system effectively degraded contaminants even in complex water with interferences and enabled selective targeting of pollutants with electron-donating groups. This innovative approach using amorphous materials offers a promising strategy for the regulation of ROS and enabling selective contaminant removal in water treatment.