Photocatalytic Materials for Air Quality Improvement

Photocatalytic materials harness light energy to drive oxidation–reduction reactions that degrade airborne contaminants, offering a sustainable route to mitigating urban pollution. Central to this technology are semiconductor catalysts, most notably titanium dioxide (TiO₂), which upon illumination generate electron–hole pairs that activate oxygen and water molecules to yield reactive oxygen species. These radicals oxidise nitrogen oxides (NOx), volatile organic compounds (VOCs) and microbial agents into benign products such as nitrate, carbon dioxide and water. Advances in nanostructuring, doping and substrate engineering have extended the light absorption range into the visible spectrum, improved charge separation and increased interfacial contact with pollutants. Applications span self-cleaning coatings, air-purifying pavements, paints and cementitious composites, with demonstrated removal efficiencies exceeding 90 % under optimal conditions. Integration of photocatalysts into construction materials leverages vast surface areas of buildings and roads for continuous passive air treatment, aligning with global priorities for cleaner urban environments and climate resilience.

Research from Nature Portfolio

Recent studies have introduced hierarchical porous magnesian substrates modified via in situ deposition of Ag/AgCl and TiO₂, yielding a composite with multi-scale porosity and strong metal–support interaction. This design achieves broad-spectrum light absorption and markedly enhanced gas-phase pollutant adsorption. Under visible and ultraviolet illumination, the material delivers reaction rates over five to thirty times higher than conventional TiO₂ catalysts. The robust synthesis protocol ensures stability of the active phase and sustained photocatalytic performance, offering a promising blueprint for next-generation air-cleaning surfaces capable of operating efficiently under ambient light conditions.

Photocatalytic Materials for Air Quality Improvement publication trend

The graph below shows the total number of articles in photocatalytic materials for air quality improvement across all publications each year (not limited to Nature Index journals).

Technical terms

Photocatalysis: Light-driven acceleration of chemical transformations on a catalyst surface via generation of reactive species.

Semiconductor: A material with a bandgap that allows excitation of electrons to conduct electricity under light illumination.

Electron–hole recombination: The process by which photogenerated electrons reunite with holes, reducing catalyst efficiency.

NOx: Collective term for nitrogen oxide pollutants (NO and NO₂) that contribute to smog and respiratory issues.

Hierarchical porous substrate: A support structure with multi-scale pore architecture that enhances surface area and mass transport.

References

1. Highly Stable Self-Cleaning Paints Based on Waste-Valorized PNC-Doped TiO2 Nanoparticles. ACS Catalysis (2024).
2. An in-situ synthesis of Ag/AgCl/TiO2/hierarchical porous magnesian material and its photocatalytic performance. Scientific Reports (2016).
3. Progress of functionalized TiO2-based nanomaterials in the construction industry: A comprehensive review. Chemical Engineering Journal (2022).