Photocatalytic Degradation in Aqueous Wastewater Treatment Systems

Photocatalytic degradation harnesses semiconductor catalysts under illumination to generate reactive species that dismantle organic pollutants in water. By combining adsorption and oxidation mechanisms, this technology targets dyes, pharmaceuticals, phenolic compounds and other recalcitrant contaminants. Advances in nanostructured materials, composite catalysts incorporating bio-derived carbon supports and visible-light-responsive oxides have bolstered charge separation, enlarged surface area and extended spectral absorption. Reactor configurations range from suspension systems to immobilised films, operating under ultraviolet or solar light to achieve mineralisation at ambient temperature without added chemicals. Such systems hold global significance for treating effluents from textile, pharmaceutical and agrochemical industries, aligning with circular water management and sustainable development objectives.

Research from Nature Portfolio

Recent studies have explored composite biochar–titania photocatalysts tailored for antibiotic removal in water. One investigation developed anatase TiO₂-loaded biochar variants via impregnation, achieving over 85% degradation of enrofloxacin under UV light and demonstrating retained activity above 77% after multiple cycles. Surface modification and alkaline activation were shown to narrow the band gap, enhance specific surface area by an order of magnitude and promote O₂•− mediated oxidation. These findings underscore the potential of hybrid carbon–metal oxide frameworks for robust, reusable catalysts in real-world effluent treatment.

Photocatalytic Degradation in Aqueous Wastewater Treatment Systems publication trend

The graph below shows the total number of articles in photocatalytic degradation in aqueous wastewater treatment systems across all publications each year (not limited to Nature Index journals).

Technical terms

Photocatalyst: A material, typically a semiconductor, that accelerates chemical reactions under light irradiation by generating charge carriers.

Band gap: The energy difference between the valence and conduction bands of a semiconductor that determines its light absorption properties.

Electron-hole pair: A pair of charge carriers created when photons excite electrons from the valence to conduction band, enabling redox reactions.

Reactive oxygen species (ROS): Highly reactive molecules, such as hydroxyl radicals and superoxide ions, formed during photocatalysis that oxidise pollutants.

Biochar: Carbon-rich porous material produced by pyrolysis of biomass, used to support catalysts and enhance adsorption and electron transfer.

Heterojunction: An interface between two semiconductor materials with different band structures, promoting charge separation and extending light response.

References

1. Preparation of TiO2-modified Biochar and its Characteristics of Photo-catalysis Degradation for Enrofloxacin. Scientific Reports (2020).
2. Recent Progress in Biochar-Based Photocatalysts for Wastewater Treatment: Synthesis, Mechanisms, and Applications. Applied Sciences (2020).
3. Photocatalytic Activity of Magnetic Nano-β-FeOOH/Fe3O4/Biochar Composites for the Enhanced Degradation of Methyl Orange Under Visible Light. Nanomaterials (2021).
4. Synthesis of ZnO Nanoparticles Loaded on Biochar Derived from Spartina alterniflora with Superior Photocatalytic Degradation Performance. Nanomaterials (2021).