Abstract:

Perovskite-type high-entropy oxides （HEPs） have significant degradation effects on some antibiotics due to their unique structure. Currently， there is a lack of research on the effects of dispersants dosages on the photocatalytic performance of HEPs prepared via sol-gel method. In this paper， La（TiMnCoNiCu）O₃ （LTMCNCO） nanoparticles with n-type semiconductor properties were synthesized by calcination at 850 ℃ by sol-gel method. The effect of dispersant ethylene glycol dosage on the performance of LTMCNCO nanoparticles was systematically studied. The results show that when the mole ratio of metal ions to ethylene glycol is 1∶2， LTMCNCO nanoparticles exhibit excellent electrochemical performance. The instantaneous photocurrent density is 3.95 μA·cm^-2， its flat band potential and band gap are -0.539 eV and 1.12 eV respectively， and the conduction band and valence band energies are -0.539 and +0.581 eV respectively. Under the driven of visible light， when the light reaction lasts for 150 min， the maximum photodegradation rates of LTMCNCO nanoparticles for 10 mg·L^-1 levofloxacin （AHS）， ciprofloxacin （CIP）， and tetracycline hydrochloride （Tc-HCl） reach 20.2%， 50.4%， and 79.9%， respectively. The free radical capture experiments indicate that the photocatalytic activity of LTMCNCO nanoparticles is mainly caused by hydroxyl radicals （·OH）， superoxide radicals （·O{}_{\mathrm{2}}^{-}） and holes （h⁺）. The narrow bandgap characteristics and lattice distortion effect of LTMCNCO nanoparticles increase the density of surface-active sites， thereby significantly improving the photocatalytic degradation efficiency of pollutants.

Key words: La（TiMnCoNiCu）O₃, high-entropy oxide, dispersant, visible-light photocatalysis, antibiotic degradation