FTO-TiO2 photoelectrocatalytic degradation of triphenyltin chloride coupled to photoelectro-Fenton: A mechanistic study

A powerful, simple and stable transparent photoanode based on TiO2 nanoparticles deposited on fluorine-doped fin oxide (FTO) was synthesized for the photoelectrocatalytic degradation of the organometallic pollutant triphenyltin chloride (TPTCl). Contrasting with most of the works on photoelectrocatalysis (PEC), FTO-TiO2 was found to be an excellent anode material for the degradation/mineralization of organic pollutants at high anodic potentials through the formation of electrochemically-induced h(vB)(+) (dark PEC), showing a similar behavior as the so-called non-active anodes like the powerful boron doped diamond electrode (BDD). The electrocatalytic efficiency was enhanced by the photoexcitation of TiO2 under UV light (PEC) and by coupling with photoelectro- Fenton (PEC-PEF): this resulted in complete degradation of TPTCl in 15 min (k(app) =0.274 min(-1)) and total mineralization in 2 h. The mechanisms governing the photoelectrocatalytic processes are investigated in detail by means of electrochemical measurements and chemical probes, and a mineralization pathway for TPTCl is proposed.