Near-infrared-activated NaYF4:Yb3+,Tm3+@g-C3N4@WO3@MXene photocatalytic system for enhanced removal of tetracycline antibiotics†

To utilize near-infrared (NIR) light within the solar energy spectrum, we have engineered an advanced composite of NaYF₄:Yb³⁺,Tm³⁺@g-C₃N₄@WO₃@MXene (denoted as NYT@g-C₃N₄@WO₃@MXene) capable of absorbing NIR light to facilitate photocatalytic reactions. This environmentally benign system integrates semiconductor heterostructures (g-C₃N₄ and WO₃) with upconversion nanoparticles (NaYF₄:Yb³⁺,Tm³⁺, abbreviated as NYT) and Ti₃C₂ MXene nanosheets. Experimental validation demonstrated exceptional performance in antibiotic remediation, with the composite achieving 86.3% tetracycline decomposition over 12 hours under NIR irradiation through synergistic mechanisms, while also exhibiting good cycling stability. The enhanced photocatalytic activity arises from collaborative effects between upconversion luminescence, optimized charge transfer pathways within the heterojunction architecture, and the visible light absorption characteristics of MXene.