Visible light-driven photoelectrocatalysis for simultaneous removal of oxytetracycline and Cu (II) based on plasmonic Bi/Bi2O3/TiO2 nanotubes.

A visible light-driven photoelectrocatalytic system was constructed based on Bi/Bi2O3/TiO2 nanotubes (NTs) to treat wastewater containing oxytetracycline and Cu2+ mixed pollutants. The surface morphology, crystal phase, elemental composition, light absorption property and photoelectrochemical activity of the synthesized Bi/Bi2O3/TiO2 NTs were investigated. The composite film, Bi/Bi2O3/TiO2 NTs was used for the photoelectrochemical removal of oxytetracycline, and it had excellent visible light photoelectrocatalytic performance. Under optimal conditions, the composite film was simultaneously used to remove coexisting oxytetracycline-Cu2+. The study results show that the reduction of Cu2+ on cathode was promoted by oxytetracycline while the degradation of oxytetracycline on photoanode was slightly suppressed by Cu2+. Also, possible photoelectrocatalytic degradation pathways for oxytetracycline-Cu2+ were analyzed by HPLC-MS.

Simultaneous removal of organic pollutants and heavy metals in wastewater by photoelectrocatalysis: A review.

As a powerful technique by combining photocatalysis with electrochemistry, photoelectrocatalysis has been extensively explored to simultaneously remove mixed pollutants of organic and heavy metal in wastewater in the past decade. In the photoelectrocatalytic system, the bias potential can remarkably promote the oxidation of organic pollutants on the photoanode by suppressing the recombination of photogenerated electron-hole pairs and extending the lifetime of photogenerated holes. Meanwhile, some photogenerated electrons are driven by the bias potential to the cathode to reduce heavy metals. In this review, we summarize the research advances in photoelectrocatalytic treatment of organic-heavy metal mixed pollution systems under UV light, visible light and sunlight. We demonstrate the main operation variables affecting the photoelectrocatalytic removal processes of organic pollutants and heavy metals. The problems for utilization of solar energy in photoelectrocatalysis are discussed. Finally, this review proposes the perspectives for future development of photoelectrocatalysis to industrial applications.