Enhanced photocatalytic and antibacterial activity of NiSe2-TiO2 nanocomposites under visible light

In this study, we have successfully prepared NiSe2-TiO2 nanocomposites with varying mass ratios, and their photocatalytic performance against the removal of RhB and inhibition of notorious E.coli is investigated under the light. Pure NiSe2 nanocubes were synthesized by a facile and cost-effective hydrothermal method, whilst pure TiO2 microspheres were fabricated by the sol-gel method. The crystalline structure, elemental composition, morphology, and optical characteristics of the samples were investigated with the help of various characterization techniques. X-ray diffraction patterns revealed the formation of NiSe2, TiO2, and their nanocomposites with high purity. Raman, EDX, and FTIR spectroscopy measurements further supported the XRD results and confirmed the successful formation of the prepared samples. Furthermore, FE-SEM images confirmed that the surface morphology of NiSe2 was comprised of nanocubes, whilst that of TiO2 was found to be microspheres. For NiSe2-TiO2 nanocomposites, the surface morphology was found to be co-existing of both nanocubes and microspheres. UV-Vis absorption spectroscopy measurements revealed that the bandgap energies reduced with increasing the mass ratios of NiSe2 in the nanocomposite samples. The photocatalytic properties of the NiSe2-TiO2 nanocomposites were evaluated under visible light by using Rhodamine B (RhB) as a model dye. Among all the nanocomposite samples, 50% NiSe2-TiO2 showed the highest photocatalytic efficiency. Moreover, the prepared nanocomposites showed superior antibacterial activities against E.coli under visible light irradiation.