Effective degradation of antibiotics using near-infrared excited nonlinear optical heterojunctions through atomic-level regulation

Developing an efficient photocatalyst that fully utilizes sunlight, especially near-infrared light, remains a major challenge. Here, a synthesis strategy for producing g-C 3 N 4 :Tm@Ba 4 Yb 3 F 17 :Tm Z-scheme composites with infrared light response composed of single atom Tm modified g-C 3 N 4 nanosheets and Ba 4 Yb 3 F 17 :Tm nanoparticles were proposed. The formation of Z-scheme heterojunctions was demonstrated by combining DFT and fs-TAS. More importantly, not only is the critical distance for energy transfer between Yb 3+ and Tm 3+ precisely controlled, but the distance required for upconversion luminescence emitted from Tm 3+ to be transmitted to g-C 3 N 4 is also precisely adjusted at the molecular level, allowing the upconversion luminescence emitted by Tm 3+ to be more effectively transmitted to g-C 3 N 4 . Under near-infrared light, the ultraviolet and blue upconversion emissions generated by Ba 4 Yb 3 F 17 :Tm can be fully absorbed by g-C 3 N 4 and generate electron–hole pairs (e − /h + ), achieving efficient energy transfer and exhibiting significant performance in the degradation of antibiotics. After 12 hours of near-infrared light exposure, the degradation efficiency of tetracycline reached 93%. The mechanisms of reaction intermediates, active species, and reaction pathways during the catalytic process have been proposed based on LC-MS/MS technology. This work provides a new scenario for the design and synthesis of catalysts with near-infrared light response characteristics.