Ag-enhanced CeF3–O: highly enhanced photocatalytic performance under NIR light irradiation.

CeF₃-O with intermediate band showed improved synergic photodegradation activity toward HCl–TC and RhB under NIR light irradiation when enhanced by Ag as a cocatalyst. Ag⁺ ions take electrons from the second transition in CeF₃–O's intermediate band, which are then reduced to Ag as cocatalyst. The photodegradation efficiencies of HCl–TC by various Ag/CeF₃–O nanoparticles in 180-min increase from 26.5 to 73.1%. The optimal Ag/CeF₃–O-100 is about 2.76 times that of pure CeF₃–O. Ag/CeF₃–O-100 has an apparent rate constant of 4.5 × 10⁻³ min⁻¹, which is 3.0 times that of pure CeF₃–O. Similarly, Ag/CeF₃–O-10 achieves a superior photodegradation efficiency of RhB at 96.7% under NIR light within 120 min. Its apparent rate constant of 27.7 × 10⁻³ min⁻¹ is 12.0 times that of pure CeF₃-O (2.3 × 10⁻³ min⁻¹). Further, the turnover frequencies of Ag/CeF₃–O nanoparticles are greatly higher than that of the corresponding pure CeF₃–O nanoparticles. Ag-enhanced CeF₃–O has a unique metal–semiconductor interface where Ag acts as a bridge for facilitating charge transfer and the separation efficiency of photogenerated carries. The synergic effect between CeF₃–O and Ag provides a practical technique for enhancing the wastewater treatment with NIR light irradiation. [ABSTRACT FROM AUTHOR]