Quantification of photocatalytically-generated hydrogen peroxide in the presence of organic electron donors: Interference and reliability considerations

Photocatalytic H2O2 production is an innovative on-site synthesis method to treat organic pollutants through Fenton-like reactions, avoiding the need and potential liability of storage transportation. Accurate quantification crucial explore mechanism photocatalytic optimize reaction parameters. In this work, three common methods (i.e., titration with potassium permanganate (KMnO4), colorimetry ammonium metavanadate (NH4VO3) or N,N-diethylp-phenylenediamine-horseradish peroxidase (DPD-POD)) were compared their susceptibility interference by seven types representative organics considered. Interference mechanisms explored based on electron-donating (Egap) electron-accepting (ELUMO) ability present organics. The accuracy KMnO4 greatly compromised aromatic compounds even at 0.1 mM due increased consumption direct oxidation. presence p-benzoquinone that directly reacts NH4VO3 DPD compromises these colorimetric methods, especially DPD-POD concentrations as low mM. should also be scrutinized in phenols significant disturbance oxidation byproducts (e.g. hydroquinone inducing immediate color disappearance). A flowchart was generated provide guidelines for selecting appropriate different water matrices treated reactions.