Enhanced photocatalytic degradation of antiviral drugs lopinavir and ritonavir by Ni doped ZnO/SiO2 nanocomposites

Abstract

A series of silica-based Ni doped ZnO nanocomposites were successfully synthesized by the co-precipitation of zinc and nickel acetate salts in the presence of urea on the surface of amorphous silica using thermo-oxidative degradation at 600 °C with a concentration of 3, 6 and 9 mmol ZnO per 1 g SiO2. The effects of the dopants and SiO2 matrix on the structure, morphology and optical properties of the composites were investigated using N2 adsorption-desorption, Raman, XRD, UV-Vis, PL, FT-IR, SEM, and TEM analyses. XRD indicated the formation of a hexagonal ZnO wurtzite structure, while Ni2+ ions substituted Zn2+ sites in the host lattice. The size of nanoparticles was in the range of 10–100 nm and showed a broad fluorescence emission at 442–433 nm. The specific surface area was 110–171 m2 g−1. The materials showed high efficiency in removing the antiviral SARS-CoV-2 drugs lopinavir (LOPI) and ritonavir (RITO) from water. The comparative photocatalytic activity showed 100 % removal of LOPI by 3-, 6- and 9-Ni-ZnO/SiO2 photocatalysts after 60, 30 and 45 min of ultraviolet light irradiation, respectively, and 60 min for RITO for all catalyst samples. The effects of inorganic ions, dissolved organics and reusability on photocatalytic degradation were also described in terms of practical applications.