Photoelectrocatalytic degradation of 2,4-dichlorophenol in a TiO2 nanotube-coated disc flow reactor

Photoelectrocatalytic (PEC) water treatment is a promising technology for organic pollution abatement. Much of the prior research focused on material discovery and optimization. However, challenges exist in scaling-up PEC processes are associated with designing reactors effective light irradiation electrode surfaces and, simultaneously, efficient configurations. We design demonstrate key reactor principles, which influence reaction mechanisms, using TiO2 nanotube-coated disc flow reactor. Degradation organochlorinated 2,4-dichlorophenol was studied as representative carcinogenic micropollutant. The synergistic photoelectrocatalytic process showed 5-fold faster degradation kinetics than solely electrocatalytic or greater 2-fold enhancement over photocatalysis alone. Applicability demonstrated wide range micropollutant concentrations almost complete abatement even at up to 25 mg L?1 2,4-dichlorophenol. Mechanistically, increase applied current density efficiency due stabilization charge carriers higher oxidants production rates system. Carboxylic acids were identified main by-products formed from cleavage phenolic ring moieties very importantly we achieved dehalogenation photoelectrocatalysis evidence chlorine heteroatoms released innocuous chloride anions. Overall, this demonstrates importance how properly orientated leverage both novel designs architectures achieve pollutant degradation.