Construction of high-efficient photoelectrocatalytic system by coupling with TiO2 nano-tubes photoanode and active carbon/polytetrafluoroethylene cathode and its enhanced photoelectrocatalytic degradation of 2,4-dichlorophene and mechanism

• Highly-ordered TiO2 NTs electrodes were fabricated through anodization strategy.
• Some critical fabricating parameters were studied through SEM images and PC degradation of 2,4-DCP.
• An efficient PEC system based on TiO2 NTs anode and AC/PTFE cathode was constructed.
• The enhanced PEC mechanism was proposed and confirmed.

In this study, highly-ordered and well-aligned TiO2 nano-tubes (TiO2 NTs) photoelectrodes were successfully fabricated through anodization strategy, followed by post-annealing treatment. Meanwhile, some critical fabricating parameters were optimized through the morphology observation of scanning electron microscope (SEM) images and photocatalytic (PC) degradation of refractory degradation of 2,4-dichlorophene (2,4-DCP) aqueous solution. Furthermore, active carbon/polytetrafluoroethylene (AC/PTFE) cathode was prepared by rolling AC powder and PTFE latex on a machine with the stainless steel as support. Subsequently, an efficient and stable photoelectrocatalytic (PEC) system based on the as-fabricated TiO2 NTs photoanode and AC/PTFE cathode was constructed for the contaminants elimination. It was found that under the optimizing fabricating parameters, the as-constructed PEC system exhibited superior PEC performance (91.1%) for the degradation of 2,4-DCP with the help of +2.0 V external potential. In addition, the enhanced PEC mechanism was proposed and confirmed in detail. This study provides a new insight to construct efficient and stable PEC system which could be a promising candidate in pollutants elimination and water splitting.