Efficient and Eco-friendly Photocatalyst from TS-1 Decorated with Carbon Dots for Degradation of Organic Dyes

Zeolites are important heterogeneous catalysts in petrochemical industries; however, research on zeolite-related photocatalysts is currently scarce due to their low utilization of visible light. Herein, a novel photocatalyst was successfully prepared by doping carbon dots (CDs) into the titanium silicalite TS-1 zeolite through the precise control of the calcination process of the organic template. In the synthesized CDs/TS-1 photocatalyst, spherical carbon dots with rich C═O groups are uniformly dispersed within the pores and on the surface of the TS-1 zeolite. In addition to the inherent photocatalytic activity originating from the TiO₄ sites in zeolite, the incorporation of carbon dots significantly broadens the photoresponse range, allows the catalyst to capture and utilize more excitation energies, and promotes the separation of hole/electron pairs. The pore structure of TS-1 effectively adsorbs dye molecules, facilitating photocatalytic reactions. Benefiting from the synergistic effect of adsorption ability and photocatalytic activity, the degradation rate of methylene blue by CDs/TS-1 can reach 94.9% within 20 min, which is higher than those of most reported zeolite-related materials. A mechanism study further revealed that superoxide radical anions (•O₂^–) and hydroxyl radicals (•OH) play significant roles in the degradation process, and the degradation process is environmentally friendly. This work provides new insights for exploring zeolite-based photocatalysts for use in green water treatment.