Novel synthesis of WSe 2 -Graphene-TiO 2 ternary nanocomposite via ultrasonic technics for high photocatalytic reduction of CO 2 into CH 3 OH.

In the present work, we report the development of a WSe2 -Graphene-TiO2 ternary nanocomposite via ultrasonic techniques and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The band-gap of the WSe2 -Graphene-TiO2 was estimated to be about 1.62 eV which is suitable for photodegradation process under under ultraviolet UV/Visible light irradiation. The photocatalytic potential of nanocomposites is investigated for CO2 reduction to CH3 OH. WSe2 -G-TiO2 with an optimum loading of graphene of 8 wt% showed the high photoactivity, gaining a total CH3 OH yield of 6.3262 µmol g-1  h-1 after 48 h. This excellent photoreduction activity is owing to the progressive synergistic relation between WSe2 /TiO2 and graphene components in our heterogeneous system.