Engineering ultra-small Cu nanoclusters on defect-rich Magnéli- TiO2-x nanoassemblies for enhanced oxytetracycline mineralization under simulated solar-light - toxicity and mechanistic insights

Nair R.R.; Thaha S.K.S.M.; Uma K.; Mangalaraja R.V.; Sathishkumar P.; Limache-Sandoval E.M.; Tseng Z.-L. · Journal of Environmental Chemical Engineering (2026) · DOI: 10.1016/j.jece.2026.125216

Resumen

The ultra-small Cu nanoclusters anchored on defect-rich TiO2-x nanoassemblies (UCuNCs/R-TiO2-x) were synthesized through hydrothermal-assisted chemical reduction approach to enhance the visible-light-driven photocatalytic degradation of oxytetracycline (OTC). The structural characterization confirmed the coexistence of anatase TiO2 and sub-stoichiometric Magnéli phases along with Ti3 + states. The microscopic analysis revealed homogeneous surface anchoring and masking of ultra-small Cu nanoclusters over the TiO2-x matrix which established the efficient interfacial charge-transfer pathways. The incorporation of Cu nanoclusters and Magnéli phases modulated the optical properties from 3.04 to 2.25 eV for UCuNCs/R-TiO2-x and extended the visible-light absorption. The incorporation of ultra-small Cu nanoclusters accelerated the photocatalytic oxidation of OTC which attained 88% of degradation within 90 min (3.5 × 10−2 min−1) under the simulated solar irradiation. The mechanistic investigations revealed that hydroxyl radicals served as the predominant reactive species responsible for the oxidative destruction of the OTC. The electrospray ionization - high resolution mass spectrometry coupled with a quadrupole time-of-flight (ESI-HRMS/QToF) analysis resolved the sequential evolution of transformation products. The defect-engineered architecture provides a promising platform for the solar-driven degradation of pharmaceutical contaminants from the aqueous environments.

Instituciones: Universidad Privada de Tacna