Photocatalytic Disinfection Techniques for Water Purification

Photocatalytic disinfection harnesses semiconductor materials to inactivate pathogens in water through light-induced generation of reactive species. Upon irradiation, photoexcited electrons and holes in the catalyst surface interact with water and dissolved oxygen to produce hydroxyl radicals, superoxide anions and other reactive oxygen species (ROS), which attack microbial cell walls, membranes and nucleic acids. Advances in material engineering have extended activity from ultraviolet to visible and near-infrared light, improving solar utilisation efficiency. Strategies such as co-doping, heterojunction assembly and interfacial Schottky junction formation have been developed to promote charge separation, suppress recombination and enhance ROS yields. Metal-free polymers and carbon nitride derivatives offer biocompatibility and environmental benignity, while composites incorporating transition-metal oxides and MXenes have demonstrated rapid microbial inactivation. Scalable reactor designs, immobilised photocatalyst coatings and dual-mode systems that combine light and mechanical energy sources further translate bench-scale innovations into practical water treatment solutions. This field has broad global significance, offering decentralised, energy-efficient disinfection for rural and resource-limited settings without chemical by-products or antimicrobial resistance concerns.

Research from Nature Portfolio

Interfacial engineering of Bi2S3/Ti3C2Tx composites has revealed that tailoring work-function differences at the semiconductor–MXene interface forms a self-driven Schottky junction, which efficiently separates photogenerated charge carriers under near-infrared light. This design yields rapid production of reactive oxygen species and achieves over 99 % inactivation of both Gram-positive and Gram-negative bacteria within minutes. In a complementary study, graphdiyne-modified TiO2 nanofibres exhibited prolonged photocatalytic antibacterial activity and osteoinductive properties, demonstrating that two-dimensional carbon allotropes can both enhance ROS generation and support biocompatibility for dual-function biomedical and water-purification applications.

Photocatalytic Disinfection Techniques for Water Purification publication trend

The graph below shows the total number of articles in photocatalytic disinfection techniques for water purification across all publications each year (not limited to Nature Index journals).

Technical terms

Photocatalysis: Acceleration of a chemical reaction by light-activated catalyst.

Reactive oxygen species (ROS): Highly reactive molecules such as hydroxyl radicals and superoxide generated during photocatalysis.

Heterojunction: Interface between two semiconductors with different band structures to promote charge separation.

Schottky junction: Metal–semiconductor interface forming an energy barrier that enhances electron–hole separation.

Bandgap: Energy difference between valence and conduction bands determining light-absorption range.

Charge carrier separation: Process of preventing recombination of photogenerated electrons and holes to sustain catalytic activity.

References

1. Water disinfection: Advances in photocatalysis and piezo/triboelectric catalysis with progressively enhanced energy utilization. SusMat (2024).
2. Interfacial engineering of Bi2S3/Ti3C2Tx MXene based on work function for rapid photo-excited bacteria-killing. Nature Communications (2021).
3. Graphdiyne-modified TiO2 nanofibers with osteoinductive and enhanced photocatalytic antibacterial activities to prevent implant infection. Nature Communications (2020).
4. Chitosan-Grafted Carbon Oxynitride Nanoparticles: Investigation of Photocatalytic Degradation and Antibacterial Activity. Polymers (2023).
5. Construction of a g-C3N4/Bi(OH)3 Heterojunction for the Enhancement of Visible Light Photocatalytic Antibacterial Activity. International Journal of Molecular Sciences (2024).