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. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

Photoelectrocatalysis, as a powerful technique combining photocatalysis with electrochemistry, has been extensively explored for simultaneous removal of organic pollutants and heavy metals in wastewater. The bias potential in the photoelectrocatalytic system can promote oxidation of organic pollutants on the photoanode and reduce heavy metals on the cathode, addressing mixed pollution issues effectively. Various research advances, operation variables, and challenges in utilizing solar energy for photoelectrocatalysis are discussed, with future industrial applications prospects proposed.