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.