Raja Mogan, T., Ho, R. Q., Pereira, V., Chong, C., Boong, S. K., Chua, E. Y. S., Lee, H. K. (2026). Harnessing slow photons in 3D silica photonic crystals for efficient and catalyst-free removal of chromophoric organic pollutants. Journal of Materials Chemistry A. https://doi.org/10.1039/D5TA09484D
Abstract:
The widespread release of chromophoric organic pollutants from industrial and municipal sources poses a critical threat to aquatic ecosystems and human health. While adsorption-based treatments offer rapid contaminant removal, they suffer from limited capacity and secondary waste generation arising from the spent adsorbent. Photocatalytic degradation provides a cleaner alternative but often relies on catalysts with poor stability and slow kinetics. Herein, we introduce a metal-free, catalyst-free water purification approach using chemically inert SiO2 inverse opal photonic crystals that integrate high-capacity adsorption with visible-light-driven pollutant degradation. The three-dimensional periodic structure facilitates rapid pollutant uptake through interconnected porosity, while photonic bandgap effects and slow photon generation dramatically enhance light confinement. This optical effect enables efficient photodegradation of pre-adsorbed chromophoric organic pollutants using only visible light. Among the tested platforms, SiO2 IO-343 demonstrates superior performance, achieving >90% adsorption within 1 hour and 95% photodegradation upon extended irradiation. Notably, its apparent reaction rate exceeds those of state-of-the-art semiconductor and hybrid photocatalysts by up to 17-fold, even though it lacks optically active or redox-functional components. Our findings position photonic crystal architectures as a promising class of robust, regenerable, and energy-efficient materials for advanced water treatment, notably offering a catalyst-free alternative for sustainable water purification.
License type:
Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Funding Info:
This research / project is supported by the Agency for Science, Technology and Research - Manufacturing, Trade, and Connectivity Individual Research Grant
Grant Reference no. : MTC IRG M23M6c0098
This research / project is supported by the Ministry of Education, Singapore - Academic Research Fund Tier 1
Grant Reference no. : RG92/24
This research / project is supported by the Nanyang Technological University - Start-up grants
Grant Reference no. :