Abstract:
In this new era, with fast expansion of present civilization along with the progression of
industrial development, environmental pollution and extreme exhaustion of energy sources has
become crucial problem. Firstly, environmental pollution (including water and air) is the most
critical problem at present day, thus the degradation of organic and toxic pollutants in solution or
in air by photocatalysis has become an effective practice to cure effect of environmental
pollution. Secondly, conservative fossil fuels at are near exhaustion. Thus, it is really important
to introduce diverse energy sources.
Here, in this work, we report various metal vanadate based oxides (Zn3V2O8, Co3V2O8 and their
composites) for the photocatalytic degradation of methylene blue, which is a major industrial
waste and pollution causing agent and energy storage device supercapacitor. Characterization of
synthesized nanomaterials was further done by various techniques including powder X-ray
diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray
spectroscopy (EDX) and UV-Visible diffused reflectance spectroscopy, X-ray photoelectron
spectroscopy (XPS), Brunauer–Emmett–Teller (BET) and Cyclovoltametry (CV).These
techniques have confirmed that nanoparticles and their nanocomposites have been synthesized
successfully. Among different synthesized photocatalysts, it was expected that nanocomposites
would show better photocatalytic and electrochemical properties as compared to their individual
counter parts. The nanomaterials and their composites were synthesized through a simplistic one
pot hydrothermal method. The electrochemical supercapacitor performance of the Zn3V2O8
nanoplatelets, Co3V2O8 nanoparticles and their composites were studied by using cyclic
voltammetry along with the galvanostatic charge-discharge studies. The shapes of the CV curves
indicate that the capacitance is mainly due to the pseudocapacitance as the CV curves do not tell
about electric double layer capacitance. Further specific capacitance and cyclic stability was
evaluated using galvanostatic charge discharge curve analysis at various current densities. All the
curves show pseudocapacitive effect because the curve shows a little deviation from isosceles
triangular shape.
