Manganese vanadate nano pebbles were prepared by a simple co-precipitation method and calcined at 350 °C for 3 h. X-ray diffraction pattern and Fourier transform infrared spectroscopic analysis ...confirmed the monoclinic structure of Mn2V2O7 with metallic bond vibrations. Morphological features of manganese vanadate nanoparticles were observed as pebble-like morphology via Scanning electron microscope and High-resolution transmission electron microscopic analysis. Oxidation states and optical property of the synthesized manganese vanadate nano pebbles was examined through UV-Visible absorption spectroscopic analysis. Pseudocapacitance nature of prepared manganese vanadate nano pebbles was investigated by cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopic techniques in 4 M aqueous KOH electrolyte. The maximum specific capacitance values of 528 Fg-1 was attained in 4 M KOH electrolyte solution at 10 mVs−1. Superior capacitive retention of about 90.1% was achieved along with 99% coulombic efficiency after 3000 continuous cycles.
•Simple chemical method was reported to prepare manganese vanadate nanopebbles.•Manganese vanadate modified electrode was fabricated on nickel foil by doctor blade technique.•Modified electrode exhibits maximum specific capacitance values of 528 Fg-1.•Highest electrochemical stability of about 90.1% was achieved after 3000 repetitive cycles.
Nano structured zinc vanadate, Zn3(VO4)2, have been successfully synthesized by simple co-precipitation method and calcined at 600 °C. Calcinated Zn3(VO4)2 nano flakes were characterized by various ...analytical techniques to examine the structural, optical, and surface morphological properties. The X-ray diffraction pattern revealed that the prepared Zn3(VO4)2 nanoparticles were orthorhombic crystalline structure and found the crystallite structure was ~44 nm. The flake shaped Zn3(VO4)2 nanoparticles was evaluated by electron microscopies such as scanning electron microscopy and high-resolution transmission electron microscopy studies. Elemental compositions and functional groups were elucidated by energy dispersive spectroscopy with mapping and Fourier transform infrared spectral studies. Electrochemical behaviour of Zn3(VO4)2 nanostructures were investigated by cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopic analysis. The specific capacitance value for the prepared nanoparticles was 312 Fg-1 with high retention of about 90.7% which was achieved after 5000th cycles. It clearly revealed that synthesized Zn3(VO4)2 nanoparticles may lead to potential application for forthcoming energy storage devices.
Pyrochlore structured nickel vanadate nanorods had been prepared by simple co-precipitation method. It was examined for pseudocapacitor electrode material. Morphological, optical and structural ...aspects of synthesized materials had been studied using a high-resolution transmission electron microscopy, UV–Visible absorption spectroscopy and powder X-ray diffraction analysis, respectively. The functional groups, stretching and bending vibrations were traced by Fourier transform infrared spectroscopy and the formation of nickel vanadate nanorods was confirmed by the binding energy analysis through X-ray photoelectron spectroscopic studies. The rod-shaped nanostructures of pyro nickel vanadate were confirmed by the scanning electron microscopy and HR-TEM analysis. Electrochemical techniques such as cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy techniques were used to analyse the supercapacitive behaviour of the prepared nanorods. Pyro nickel vanadate nanorods possesses excellent electrochemical stability up to 3000 cycles and the performance retention of about 94.1% was achieved even after 3000 repetitive charge-discharge cycles.
ZnO nanorods embedded on functionalized CNT have been synthesised by the chemical refluxing method. The characterization results revealed the tube-like structure of carbon nanotubes, that expose the ...ZnO nanorods grafted upright and parallel on the floor across the CNT surface. The powder X-ray diffraction patterns show that crystalline ZnO nanorods are highly loaded on the surface of CNT and formed as a nano-composite. Raman spectroscopy results showed that the intensity of D and G bands decreased due to the loading of ZnO nanorods. Cyclic voltammetry curves reveal the double layer capacitor (EDLC) behaviour of ZnO/CNT. The synthesised hybrid ZnO/CNT exhibits a high specific capacitance (SPc) of 189 Fg-1. The quick charge-discharge performance was found about 95 Fg-1 and the cyclic stability of 96% was observed for 1000 cycles. ZnO/CNT nano-composites also exhibit a high power density of 2250 W kg-1.
•Uniform shape and size ZnO nanorod decorated on functionalized CNT was synthesised.•Electrochemical behaviour of ZnO/CNT was studied (CV, GCD and ESI) in Na2SO4 electrolyte.•EDLC specific capacitance was found to be 189 F/g at 1 mVs−1.•High power density of 2250 W/Kg with energy density of 10.7 Wh/Kg was found.•Cyclic life with retention of capacitance was found about 96% after 1000 cycles.
The present work reports the structural, morphological, and optical analysis of rare earth metal ion (Nd3+) doped Titanium Dioxide Nanoparticles. Titanium Dioxide doped with Neodymium ions (1 wt% and ...4 wt%) have been studied by X-ray diffraction (XRD) Aanlysis, High Resolution Transmission Electron Microscopy (HR-TEM) analysis, Energy Dispersive X-ray Analysis (EDAX), Ultraviolet–visible (UV–Vis) spectroscopic analysis. The powder X-ray diffraction patterns ensured the nanocrystalline anatase formation of all the samples. The morphology and particle size of the TiO2 host matrix were confirmed by High Resolution Transmission emission electron microscopy (HR-TEM). The particle size trend obtained from HR- TEM images is acceptable with the crystal size obtained from XRD results. Ultraviolet–visible measurements were carried out to investigate the optical properties of our powdered titania. The dye sensitized solar cells were fabricated with these as-synthesized materials as the photoanode and the J-V measurement shows improved high open circuit voltage, short circuit current and high efficiency achieved.
The aim of the present work is to investigate the influence of Samarium ions doping in the TiO2 host lattice and the contribution to the optical properties of this semiconductor. The X-ray ...diffraction pattern shows the formation of anatase phase TiO2 nanoparticles of average sizes 7.8 nm, 7.21 nm and 6.1 nm for both pure and 1 wt% and 4 wt% of Sm3+ doped samples respectivity. Energy Dispersive X-ray (EDX) spectroscopy confirms the presence of Sm ions within the Sm substituted TiO2 nanoparticles. These results suggest that, Pure and doped TiO2 samples confirm anatase phase of good crystallinity with smaller crystallite size. UV–visible spectra display stronger absorption in the visible region. The photocatalytic experiments are investigated by the removal of rhodamine B under UV light. Compared to the other two photocatalysts, the results shows that 4 wt% of Sm3+ doped TiO2 exposes the highest photocatalytic performance.
In the present study, Pure and (1 wt% and 4 wt%) Gadolinium (Gd3+) doped TiO2 nanoparticles were developed with a hydrothermal method, and dye sensitized solar cells were fabricated using them as an ...electron transfer material. The anatase phase and structural property of pure and Gd3+ doped TiO2 nanoparticles were examined using XRD analysis. Energy Dispersive X-ray analysis (EDAX) confirmed the presence of titania nanoparticles and UV–Vis absorption spectroscopy was used for the investigation of the optical properties of synthesized photocatalysts. The photovoltaic performance of Gd3+:TiO2 based solar cells is improved compared to un-doped TiO2 based solar cell. The power conversion efficiency of the solar cells on Gd3+:TiO2 increased to 4.88%, which is higher than that of the solar cells based on un-doped TiO2.
High-performance energy storage electrode materials are emerging demand in near future for the construction of supercapacitor with high energy and power densities. Herein, Nickel (II) ...Diethyldithiocarbamate was used as single-source precursor for Nickel Sulfide (Ni
9
S
8
) two-dimensional (2D) nanosheets (NSs) preparation and hexadecylamine as shape directing agent via simple solvothermal method. The orthorhombic structure of Ni
9
S
8
NSs was confirmed by X-ray diffraction (XRD) pattern. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed that as-prepared Ni
9
S
8
nanoparticles possess sheet-like morphology. Besides, the thermal stability of Ni(DTC)
2
complex was studied by Thermogravimetric/Derivative Thermogravimetric (TG/DTG) with differential scanning calorimetric (DSC) analysis. The electrochemical properties of Ni
9
S
8
NSs was studied using galvanostatic charge–discharge (GCD) and cyclic voltammetry (CV) techniques. From the charge–discharge study of Ni
9
S
8
NSs, a high specific capacitance of 281 Fg
−1
was obtained at a current density of 1 Ag
−1
and up to 82% retentivity was achieved after 5000 cycles. Thus, the prepared Ni
9
S
8
NSs could be the one of the attractive potential active electrode materials for the application of supercapacitor.
The nanostructured cobalt hydroxide Co(OH)2 embedded carbon nanotubes (CNT) have been synthesised by a simple chemical reflux method. The crystallinity of cobalt hydroxide has been confirmed by using ...powder X-ray diffraction data. The presence of CNT in the synthesised nanocomposite is also examined. Fourier transform infrared spectroscopy reveals the OH and CoO vibrations in the Co(OH)2/fCNT nanocomposite. SEM and TEM images expose the surface morphology of Co(OH)2 sheet that is embedded over carbon nanotube. The electrochemical performance of the Co(OH)2 embedded fCNT has been examined by the cyclic voltammetry in 6 M potassium hydroxide (KOH) electrolyte in room temperature. Co(OH)2 embedded fCNT nanocomposite exhibits higher specific capacitance up to 1006.8 F/g at 0.5 mV s−1 scan rate. The specific capacitance of Co(OH)2 embedded fCNT nanocomposite is calculated from the charge-discharge curve. The synthesised hybrid nanocomposite is used as a cathode, and the functionalized CNT is used as an anode. These are used to fabricate an asymmetrical supercapacitor device. The device is delivered to a high power density of 7000 W kg−1 and energy density of 17 W h kg−1 in the potential window from 0 V to 1.4 V. The results of hybrid Co(OH)2/fCNT||fCNT asymmetrical supercapacitor exhibit better cycle stability up to 5000 cycles. The usefulness of Co(OH)2/fCNT||fCNT asymmetrical supercapacitor is analysed for energy storage devices.
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•Co(OH)2 embedded carbon nanotube nanocomposite was synthesised.•A peak specific capacitance of 1006.8 F g−1 was found to Co(OH)2/fCNT.•Asymmetrical supercapacitor device of fCNT||Co(OH)2/fCNT was fabricated.•Device exhibits high power and energy density about 7000 W kg−1 and 17 W h kg−1.•Device exhibits 84% energy retention in cyclic test after 5000 cycles.
In the present work, hydrothermal method was followed to synthesize Undoped and Dy
3+
doped TiO
2
nanoparticles. The as-prepared pure and doped nanoparticles were investigated by the characterization ...techniques, as such X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Energy dispersive X-ray analysis (EDAX), Ultraviolet–Visible (UV–Vis) spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), and Dielectric Spectroscopy. The crystallography and grain size have been studied using XRD and TEM Analysis. X-ray diffraction and energy dispersive X-ray spectroscopy results showed that the as prepared nanoparticles were without any impurity. With the doping of Dysprosium ion, the grain size increases. UV–Visible Spectra reveals the optical properties and the optical band gap calculated using Kubelka- Munk plot was found to be 3.45 eV for pure TiO
2
and decreases to 3.39 eV due to doping. The results indicate that the size of the nanoparticles increases with decreasing bandgap when dopant added. The development of the anatase phase TiO
2
is affirmed by XRD and FT-IR. The Dielectric properties and A.C Conductivity measurements along with frequency were done for synthesized samples.
