Photoelectrocatalytic Degradation of Organic Pollutants

Photoelectrocatalytic degradation of organic pollutants represents a hybrid approach that marries heterogeneous photocatalysis with electrochemical enhancement to achieve efficient and complete removal of recalcitrant compounds from water. In this process, a semiconductor photoelectrode absorbs photons to generate electron–hole pairs, which drive oxidation and reduction reactions at its surface. Application of an external bias promotes charge separation, suppresses recombination and increases the yield of reactive oxygen species such as hydroxyl radicals. These radicals attack dyes, pharmaceuticals, pesticides and other persistent organics, ultimately yielding simpler molecules or achieving full mineralisation to carbon dioxide, water and inorganic ions. Research has progressed from ultraviolet-active titanium dioxide systems to visible-light-responsive materials via doping, heterojunction formation and co-catalyst integration. Reactor designs have evolved to balance photon transport, electric-field distribution and mass transfer, with flow-through and immobilised configurations developed to facilitate scale-up. Coupling with complementary methods such as electro-Fenton treatments, energy recovery modules or renewable energy sources aims to improve both efficiency and sustainability. Despite advancements in material innovation and mechanistic insight, challenges remain in optimising long-term stability, reducing operational costs and translating laboratory-scale systems into industrial water-treatment solutions.

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Photoelectrocatalytic Degradation of Organic Pollutants publication trend

The graph below shows the total number of articles in photoelectrocatalytic degradation of organic pollutants across all publications each year (not limited to Nature Index journals).

Technical terms

Photoelectrocatalysis: An advanced oxidation process combining light-driven semiconductor catalysis with an applied electrical bias to enhance charge separation and generate reactive species for pollutant degradation.

Photoanode: A semiconductor electrode that absorbs light and acts as the oxidising site in a photoelectrocatalytic cell, generating electron–hole pairs under illumination.

Reactive Oxygen Species (ROS): Highly reactive molecules such as hydroxyl radicals and superoxide ions produced during photoelectrocatalysis that attack and break down organic contaminants.

Electron–hole recombination: The undesirable process by which photogenerated electrons and holes recombine without participating in chemical reactions, reducing overall efficiency.

Mineralisation: The complete oxidation of organic pollutants to inorganic end-products such as carbon dioxide, water and mineral acids or salts.

References

1. Investigating the effectiveness of bifacial mixed metal MOF electrodes for the photoelectro-catalytic treatment of municipal wastewater. Journal of Cleaner Production (2023).
2. The application of photoelectrocatalysis in the degradation of rhodamine B in aqueous solutions: a review. RSC Advances (2022).
3. A Review of Photoelectrocatalytic Reactors for Water and Wastewater Treatment. Water (2021).
4. Semiconductor Electrode Materials Applied in Photoelectrocatalytic Wastewater Treatment—an Overview. Catalysts (2020).