Photo-Fenton degradation assisted by in situ generation of hydrogen peroxide using a carbon nitride photocatalyst

Metal-free carbon nitride photocatalysts can generate hydrogen peroxide (H2O2) in the presence of dissolved oxygen and visible light radiation. H2O2 leads to the formation of hydroxyl radicals, which can mineralize phenolic compounds in the liquid phase. Adding dissolved iron into the mixture promotes the classical Fenton reaction, improving the degradation process. Low dosages of dissolved iron added to the carbon nitride photocatalytic system can enhance similar to 1.2 times the mineralization of resorcinol, phenol, gallic acid, and benzoic acid (phenolic compounds) at its natural pH. The system is self-sufficient, using on-site heterogeneous photocatalytically synthesised H2O2, which induces homogenous Fenton reactions without acidifying the effluents.