Oxygen doped graphitic carbon nitride nanosheets for the degradation of organic pollutants by activating hydrogen peroxide in the presence of bicarbonate in the dark

Abstract

The development of novel wastewater treatment processes that use heterogeneous catalysts to activate hydrogen peroxide (H₂O₂) with bicarbonate (HCO₃⁻) has been a subject of great interest in recent years; however, significant challenges remain, despite research into numerous metal-based catalysts. The work presented herein employed oxygen-doped graphitic carbon nitride (O/g-C₃N₄) as a non-metal catalyst for activating H₂O₂ in the presence of HCO₃⁻, and this method represented the first system capable of removing organic pollutants in the dark, to our knowledge. The catalysts were characterized using several microscopic imaging, spectroscopic, electrochemical, and crystallographic techniques, as well as N₂-physorption procedures. Analysis of the results revealed that the O/g-C₃N₄ catalyst possessed a high specific surface area and many defect sites. Various operational parameters, including the relative amounts of HCO₃⁻, H₂O₂, and O/g-C₃N₄, were systemically investigated. A clear performance enhancement was observed in the degradation of organic contaminants when subjected to the HCO₃⁻–H₂O₂–O/g-C₃N₄ system, and this result was ascribed to the synchronous adsorption and chemical oxidation processes. The novel system presented herein represented a new water treatment technology that was effective for removing organic contaminants.