Facile in-situ microwave irradiation synthesis of TiO^sub 2^/graphene nanocomposite for high-performance supercapacitor applications

In this work, TiO2/graphene nanocomposite was synthesized by facile, surfactant free, in-situ microwave irradiation method, a quick but also are eco-friendly approach. The structure, morphology, composition and thermal stability of the composites were characterized by using XRD, SEM, FT-IR, Raman spectroscopy, and TGA analyses. XRD result shows the tetragonal anatase phase of pure TiO2, TiO2 in the composite and their crystallite size were estimated to be 2.8 and 2 nm respectively. The SEM and HR-TEM analyses demonstrate the spherical TiO2 nanoparticles intercalated on the graphene sheets. TGA results reveal higher thermal stability of the TiO2/graphene nanocomposite over graphene oxide and TiO2 nanoparticles. XPS studies confirm the binding states of the composite structure. The nanocomposites used as the supercapacitor electrode in three electrode system exhibited higher specific capacitance value of 585 Fg− 1 at a current density of 1 Ag− 1 in 1 M H2SO4 as compared to graphene oxide (174 Fg− 1) and TiO2 electrode (66 Fg− 1). The enhanced capacitive performance is due to the intercalation of TiO2 nanoparticles on the graphene sheet. The in-situ microwave irradiation method brings a viable, low-cost and facile synthesis of different metal oxide/graphene based composites with promising properties for energy-storage applications in supercapacitors.