In the present work, we have synthesized three-dimensional (3D) reduced graphene oxide nanosheets (rGO NSs) containing iron oxide nanoparticles (FeO NPs) hybrids (3D FeO/rGO) by one-pot microwave approach. Structural and morphological studies reveal that the as-synthesized FeO/rGO hybrids were composed of faceted FeO NPs induced into the interconnected network of rGO NSs. The morphologies and structures of the 3D hybrids have been characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectrometer (XPS). The electrochemical studies were analyzed by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy, which demonstrate superior electrochemical performance as supercapacitors electrode application. The specific capacitances of 3D hybrid materials was 455 F g at the scan rate of 8 mV s, which is superior to that of bare FeO NPs. Additionally, the 3D hybrid shows good cycling stability with a retention ratio of 91.4 after starting from ∼190 cycles up to 9600 cycles. These attractive results suggest that this 3D FeO/rGO hybrid shows better performance as an electrode material for high-performance supercapacitors.

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The introduction of a dense TiO 2 layer between the mesoporous TiO 2 network and the charge collector in dye-sensitized solar cell anodes has been claimed to improve the performance of solar cell devices. Two mechanisms have been proposed to explain this behavior, a decrease in the electron−hole recombination at substrate/electrolyte interface and an enhancement in the electronic contact between the mesoporous TiO 2 network and the charge collecting electrode. In this work the effect of sputtered TiO 2 blocking layers (BLs) on the performance of dye-sensitized solar cells electrodes has been analyzed. It has been shown that the electron injection efficiency governed changes observed in cell efficiency. The thicker the BL, the poorer the photocurrent, and therefore, only thin BLs leaded to an increase in energy conversion efficiencies. The thickness of the BL also affected the internal series resistance of the solar cells, influencing their fill factor.

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