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The microstructure of photoelectrode plays a crucial role in the performance of Dye Sensitized Solar Cells (DSSCs). The uneven morphology of FTO (Fluorine doped tin oxide) glass and high porosity of TiO2 layer will produce defects such as tiny gaps, pores and cavities in FTO/TiO2 interface which allows for direct penetration of the electrolyte to the surface of FTO, leading to the recombination of electrons. To address this issue some work has been conducted to functionalize FTO glass with graphene because of its exceptional mobility and transparency. However, this approach is not feasible as graphene nanosheets is economically quite expensive. Therefore, in the current study, graphene nanosheets is replaced with graphene nanoplatelets (GNPs) in order to modify the FTO/TiO2 interface by providing conducting bridges to photo-injected electrons and impede the excessive penetration of the electrolyte. The conversion efficiency for GNP modified interface was found to be 2.32% (active area of 1 cm2), which is 19.75% higher than the conventionally prepared DSSC. Electrochemical Impedance Spectroscopy (EIS) spectra revealed that the GNP based cell has lesser total internal resistance compared to the conventional one. [ABSTRACT FROM AUTHOR]

Hydrogen production by splitting of water using solar means is a renewable alternative and is a need of the hour. The generation of hydrogen is studied using nanostructured V2O5/TiO2 bilayer photoctatalyst synthesized by two different methods. The solution deposition followed by annealing and flame oxidized methods are applied to deposit the nanostructured V2O5 onto TiO2 nanorod arrays. These two methods are compared and studied using X-ray diffraction, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), electron energy loss spectrum and photoelectrochemical study. The morphological study provides the optimized surface area of the TiO2 nanorod arrays. It shows that 0.45 mL tetra butyl titanate at 180C shows the improved surface area. It also differentiates the 3D network as morphology of nanostructured V2O5/TiO2 bilayer photoctatalyst synthesized by flame oxidation method. Electron energy loss spectrum confirms the presence of respective elemental states of V2O5/TiO2 bilayer photoctatalyst. Photoelectrochemical studies show the photocurrent density of 7.89µA/cm2 at 0 V vs Ag/AgCl using flame oxidized nanostructured V2O5/TiO2 nanorod arrays. This study explores the potential of flame oxidized synthesis of nanostructured photocatalysts. [ABSTRACT FROM AUTHOR]