Mechanistic evaluation of arsenite oxidation in TiO2 assisted photocatalysis.

摘要: We report herein a detailed assessment of the roles O2, H2O2, •OH, and O2-• in TiO2 assisted photocatalytic oxidation (PCO) arsenite. Although both arsenite, As(III), arsenate, As(V), adsorb extensively onto surface TiO2, past studies relied primarily on analysis arsenic species solution, neglecting those adsorbed TiO2. used extraction analyses to illustrate that As(III) As(V) occurs an state during PCO. The deoxygenated solutions with electron scavengers, Cu2+, polyoxometalates (POM) yields rates are comparable observed under oxygen saturation, implying primary role is as scavenger conduction band electron. Pulse radiolysis competition kinetics were employed determine rate constant 3.6 × 106 M-1 s-1 for reaction ...