Synthesis of titanium dioxide/reduced graphene oxide nanocomposite by ultrasound-assisted mechanical mixing method for fabricating photoanode to upgrade the performance and stability of dye-sensitized solar cell

Abstract

• TiO 2 /rGO was successfully synthesized by ultrasound-asissted mechanical mixing method. • 1.0 wt.% rGO under 720-W ultrasonic power was optimal synthesis conditions. • The presence of rGO enhanced and stabilized DSSC performance. • Nano-sized TiO 2 paticles were evenly anchored on rGO sheets. • rGO could enhance the thermostability and photostability of the DSSC. Herein, titanium dioxide/reduced graphene oxide (TiO 2 /rGO – TG) nanocomposite was synthesized via the ultrasound-assisted mechanical mixing method, used for the fabrication of photoanode in dye-sensitized solar cells (DSSCs). The DSSCs performance was evaluated by current density-voltage (J-V) curves and electrochemical impedance spectroscopy (EIS), showing that the sample with 1.0 wt.% rGO under the ultrasonic power of 720 W, was an optimal material for fabricating photoanode in DSSCs, which obtained the power conversion efficiency of 6.37 %. Additionally, in the 500-hour illumination test under 300-watt metal-halide lamp and the 100-hour drying at 85 °C, DSSCs with the presence of rGO proved better stability in comparison with DSSCs fabricated from commercial TiO 2 . The characterization of TG was analyzed by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, indicating that TiO 2 nanoparticles are uniformly distributed onto the rGO sheets with the average diameter from 20 to 70 nm.