We present an efficient electrocatalytic material based on anchored MoO3 nanoparticles on reduced graphene oxide (RGO) nanosheets. After preparation of graphene oxide (GO), the MoO3 nanoparticles anchored on GO nanosheet by using the arc-discharge method. X-ray diffraction patterns show that the MoO3 nanoparticles are well crystallized on RGO in the orthorhombic crystalline phase with a crystallite size of 83 nm. In addition, FT-IR and Raman spectroscopy results show that during the arc-discharge process, the GO nanosheets have been reduced and RGO nanosheets are decorated with MoO3 nanoparticles which form a porous structure. The surface energy of the prepared electrode was measured as 44.56 mJ/m 2 , which shows the desirable spreading ability of the electrolyte on the electrode. Finally, electrochemical performance was measured in the symmetrical dummy cell by impedance spectroscopy and cyclic voltammogram, and the photochemical test was measured in the dye-sensitized solar cell by current density measurement. Our results show that the electrochemical performance of the RGM electrode is better than the RGO electrode and is comparable with the Platinum electrode and also the efficiency of RGM electrode used in a dye-sensitized solar cell as a counter electrode is 5.55% near to Platinum electrode performance.

In this article, the wettability of a superhydrophobic layer from rubber-modified TiO 2 /SiO 2 nanocomposite is studied. The nanocomposites were prepared with various ratios of TiO 2 and SiO 2 nanoparticles (NPs) and then studied the effect of annealing, UV irradiation and aging after coating on a substrate. Results show that the average contact angle of deionized water droplets on the most hydrophobic coating is 129.5°, which increases up to 151.0°by UV irradiation. In addition, the lowest surface energy of the prepared layers was measured as 29.61 mJ m -2 . The hydrophobicity of the coating surface was investigated after annealing (at temperatures up to 300°C), and results show that the maximum contact angle is about 150°. The dynamics of water droplets on the most hydrophobic coating were investigated by rapid imaging, and results show no hysteresis for surface wetting. Fourier transform infrared spectroscopy shows that UV irradiation causes the formation of C-H functional groups on the surface without considerable change in the hydrophobicity, while the annealing process has no significant effects on the functional groups. The morphology of the coatings was investigated by scanning electron microscopy, and results reveal that the roughness of surfaces increases due to annealing and UV radiation. In addition, a minimum increase in the roughness coefficient is estimated as 73% of the initial value after annealing, which is in agreement with atomic force microscopy results.

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