Titanium-based photocatalytic materials are synthesized to measure the photocatalytic activity against ochratoxin A (OTA) and the degradation products of OTA after photocatalysis are identified. The NaYF₄:Yb, Tm nanoparticles coated with anatase TiO 2 (NaYF₄:Yb,Tm@TiO₂) are synthesized by hydrolysis of the titanium precursor to form a core-shell composite. The synthesized composite are characterized by TEM, XRD, UV-Vis DRS and FL. Under UV-Vis-NIR (200~2500 nm) irradiation, NaYF 4:Yb,Tm@TiO₂ have a photocatalytic degradation effect and result in production of strong oxidizing free radicals, which can effectively degrade the OTA. After further optimization, the optimum loading of catalyst is found to be 10 mg/mL. Under pH of 6.2 and 500 W xenon lamp (light source), the photocatalytic degradation efficiency of 5 μg/mL OTA can reach up to 98.7% after 30 min. This photocatalytic reaction follows the first-order kinetics. Two products C₁₁H₉O₅Cl and C₁₉H₁₇ClNO₄ are formed during the OTA degradation, which have been assessed by ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry, the mass-to-charge ratios (m/z) are 256.015 and 360.061, respectively. The present study may open a new avenue to degrade other toxin.

NaYF₄:Yb,Tm@TiO₂  /  upconversion  /  photocatalysis technology  /  ochratoxin A