Manipulating carbon defects for rapid H2O2 and ·OH formation: A strategy for efficient electrocatalytic organic pollutant degradation

Abstract

Recently, carbon-based materials (CNMs) have garnered significant interest within the domain of electrocatalytic pollutant remediation. However, the ambiguity surrounding the specific active sites on CNMs hinders the enhancement of their oxidation capabilities. Here, a series of samples were designed to elucidate the actual sites by manipulating the quantity of oxygen-containing functional groups and carbon defects on CNMs (DRG-x). Among the DRG-x, DRG-600 demonstrated superior activity in hydrogen peroxide (H₂O₂) generation, and exhibited the highest kinetic activity for tetracycline degradation. Interestingly, carbon defects, rather than oxygen − containing functional groups, predominantly boosted the generation of H₂O₂ and hydroxyl radicals (·OH), thereby endowing it with exceptional pollutant removal efficiency. Besides, through the systematic determinations of reactive oxygen species (H₂O₂, ·OH and singlet oxygen) within the electrolyte, it was evident that ·OH constitutes 79.3% and plays a pivotal role in the degradation process. This work provided a reference for strategically enhancing the activity of CNMs, particularly in terms of augmenting its electrocatalytic performance and organic degradation capabilities.