Dual-wavelength LED synergy-tailored charge dynamics and reactive species modulation for a high-performance...

Photocatalytic ceramic membranes offer a promising route to advanced water treatment, yet their effectiveness is often undermined by inefficient reactive oxygen species (ROS) generation and susceptibility to quenching in complex water matrices. This study developed a Fe-TiO₂-loaded ceramic membrane (Fe-TiO₂@CM) coupled with a dual-wavelength UV-LED system (265 nm and 365 nm) to investigate wavelength-dependent charge dynamics and ROS formation pathways for the degradation of bezafibrate, a representative recalcitrant pharmaceutical contaminant. Under 265 nm irradiation, the results support substantial involvement of •OH in fast oxidation, driving fast degradation and mineralization. Under 365 nm irradiation, oxygen-vacancy/Fe-related processes preferentially indicate major involvement of ¹O₂-related nonradical pathways with enhanced resistance to matrix interference. Dual-wavelength synergy achieves complementary photon utilization and spatial separation of charge carriers, while Fe-related processes and oxygen-vacancy-mediated electron transfer collectively enhance anti-quenching performance and fouling control. These findings establish a mechanistic basis for multi-wavelength spectral engineering in photocatalytic membranes, and offer a practical pathway toward efficient, environmentally adaptive water-treatment systems.