Chemical synthesis of Ni/TiO2 nanophotocatalyst for UV/visible light assisted degradation of organic dye in aqueous solution

Abstract

The Ni/TiO2 nanoparticles with different Ni dopant content were prepared by a modified sol–gel method. The structure and photoinduced charge properties of the as-prepared catalysts were determined using X-ray diffraction, transmission electron microscopy, UV–vis diffuse reflectance spectroscopy and surface photovoltage spectroscopy techniques, and the photocatalytic efficiency of these catalysts was tested using an organic dye. It was shown that Ni modification could greatly enhance the photocatalytic efficiency of these nanocomposite catalysts by taking the photodegradation of methyl orange as a model reaction. With appropriate ratio of Ni and TiO2, Ni/TiO2 nanocomposites showed the superior photocatalytic activity than the single TiO2 nanoparticles. Surface photovoltage spectra demonstrated that Ni modification could effectively inhibit the recombination of the photoinduced electron and holes of TiO2. This electron–hole pair separation conditions are responsible for the higher photocatalytic performance of Ni/TiO2 nanocomposites in the visible region of electromagnetic spectrum.