Punicalagin Green Functionalized Cu/Cu2O/ZnO/CuO Nanocomposite for Potential Electrochemical Transducer and Catalyst.

X Fuku,K Kaviyarasu,M Maaza,N Matinise

doi:10.1186/s11671-016-1581-8

Abstract

A novel ternary Punica granatum L-Cu/Cu2O/CuO/ZnO nanocomposite was successfully synthesised via green route. In this work, we demonstrate that the green synthesis of metal oxides is more viable and facile compare to other methods, i.e., physical and chemical routes while presenting a potential electrode for energy applications. The prepared nanocomposite was characterised by both microscopic and spectroscopic techniques. High-resolution scanning electron microscopy (HRSEM) and X-ray diffraction (XRD) techniques revealed different transitional phases with an average nanocrystallite size of 29–20 mm. It was observed that the nanocomposites changed from amorphous-slightly crystalline Cu/Cu2O to polycrystalline Cu/Cu2O/CuO/ZnO at different calcination temperatures (room temperature-RT- 600 °C). The Cu/Cu2O/ZnO/CuO metal oxides proved to be highly crystalline and showed irregularly distributed particles with different sizes. Meanwhile, Fourier transform infrared (FTIR) spectroscopy confirmed the purity while together with ultraviolet-visible (UV-Vis) spectroscopy proved the proposed mechanism of the synthesised nanocomposite. UV-Vis showed improved catalytic activity of the prepared metal oxides, evident by narrow band gap energy. The redox and electrochemical properties of the prepared nanocomposite were achieved by cyclic voltammetry (CV), electrochemical impedance (EIS) and galvanostatic charge-discharge (GCD). The maximum specific capacitance (Cs) was calculated to be 241 F g−1 at 50 mV s−1 for Cu/Cu2O/CuO/ZnO nanoplatelets structured electrode. Moreover, all the CuO nanostructures reveal better power performance, excellent rate as well as long term cycling stability. Such a study will encourages a new design for a wide spectrum of materials for smart electronic device applications.

Highlights

In recent times, the union between nanotechnology and biology has shaped a new ground of nanobiotechnology that integrates the use of biological bodies in a number of chemical and physical processes [1–4]
The results prove that the green route is the ease of use and can be successfully employed in the preparation of different metal oxides
TEM and X-ray diffraction (XRD) techniques were able to determine the crystallinity and particle size of the as-synthesised ternary nanocomposite while Punica granatum L peel extract used as a capping agent render the nano-oxides soluble and stable

Summary

Introduction

The union between nanotechnology and biology has shaped a new ground of nanobiotechnology that integrates the use of biological bodies (i.e., bacteria, fungi, viruses, yeasts and plants) in a number of chemical and physical processes [1–4]. There are numerous reports on chemically and physically prepared nanocrystalline copper-zinc based oxides [1, 10, 15, 20]. As far as we know, there are no green prepared binary/ternary copper-zinc oxide nanocomposites which have been reported. The first-time green synthesised Cu/Cu2O and Cu/ Cu2O/CuO/ZnO nanocomposite reveals a new route of synthesising the binary and ternary metal oxides relative to the chemical/physically modified routes. The investigation will dwell much on the structural, morphological and electrochemical properties of the prepared Cu/Cu2O/CuO/ZnO system. It will include the determination of a plausible mechanism of interaction between the biological entities and the nanocomposites

Methods

Results

Conclusion