Graphene oxide based nickel chromite nanocomposite (GONC) was synthesized via a cost effective chemical co-precipitation method for energy storage applications. As-synthesized nanomaterial was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, an elemental composition diagnostic via energy dispersive spectrscopy, optical properties via raman spectroscopy, bandgap transition measurements via photoluminescence spectroscopy, and electrochemical impedance spectroscopy and cyclic voltammetry to measure electron-transfer resistance and electrochemical active surface area. A grain size value of about 1.55 nm with nickel particles aggregation over graphene oxide surface results in nickel non-homogenous distribution with spherical grains. This leads to structural defects resulting in a downward shift at about 1430 cm −1 as observed via raman spectra. Also, a electrochemical active surface area of 0.08 cm 2 comparable to GCE surface area leads to better conductivity with a decrease in Rct upto 5.4 KΩ. It is therefore considered to be an ideal material with optimized parameters to be synthesized as tested for energy storage applications.

No abstract

MXene/Ag2CrO4 nanocomposite was synthesized effectively by means of superficial low-cost co-precipitation technique in order to inspect its capacitive storage potential for supercapacitors. MXene was etched from MAX powder and Ag2CrO4 spinel was synthesized by an easy sol-gel scheme. X-Ray diffraction (XRD) revealed an addition in inter-planar spacing from 4.7 Å to 6.2 Å while Ag2CrO4 nanoparticles diffused in form of clusters over MXene layers that had been explored by scanning electron microscopy (SEM). Energy dispersive X-Ray (EDX) demonstrated the elemental analysis. Raman spectroscopy opens the gap between bonding structure of as-synthesized nanocomposite. From photoluminence (PL) spectra the energy band gap value 3.86 eV was estimated. Electrode properties were characterized by applying electrochemical observations such as cyclic voltammetry along with electrochemical impedance spectroscopy (EIS) for understanding redox mechanism and electron transfer rate constant Kapp. Additionally, this novel work will be an assessment to analyze the capacitive behavior of electrode in different electrolytes such as in acidic of 0.1 M H2SO4 has specific capacitance Csp = 525 F/g at 10 mVs−1 and much low value in basic of 1 M KOH electrolyte. This paper reflects the novel synthesis and applications of MXene/Ag2CrO4 nanocomposite electrode fabrication in energy storage devices such as supercapacitors.

Summary Unique and significant properties of layered two‐dimensional titanium carbide MXene (Ti3C2) triggered world for designing and fabricating nanoelectrode materials with maximum energy storage capacity employed in various electrochemical device applications such as supercapacitors (SCs). In the present study, novel MXene/CoCr2O4 synthesis to fabricate nanoelectrode material via chemical co‐precipitation method with maximum stability and conductivity has been reported. Synthesized material shows reduction in c‐lattice parameter for MXene/CoCr2O4 nanocomposite to 21.7 A° indicated by X‐ray powder diffraction. Surface morphology reveals reduction in grain size up to 1.16 nm whereas elemental composition confirms presence of oxygen, titanium, chromium, and cobalt within nanocomposite. From Pl spectra, it is quite clear that peak intensity has been reduced whereas Raman spectra reveals both MXene and cobalt peaks presence within nanocomposite. Optimized nanocomposite reveals improved specific capacitance of 417 Fg−1 in IM KOH aqueous electrolyte. GCD analysis reveals power density increases from 603.2 to 1367.6 W/kg whereas energy density value decreases from 20.89 to 9.22 Wh/kg. Superior electrochemical performance of as‐prepared nanocomposite nano‐electrode material attributed to surface redox reaction supporting pseudocapacitance more strongly in basic electrolyte than acidic electrolyte. Thus, MXene/CoCr2O4 nanocomposite could serve as an excellent energy storage material especially in supercapacitors.

No abstract

Magnesium doped copper chromites spinel nanoparticles (Cu1−xMgxCr2O4) where x = 0.2, 0.4, 0.6, and 0.8 is synthesized by sol-gel method and characterized by different techniques like EDS, SEM, Raman spectroscopy, and Photoluminense. Various parameters affecting the sample techniques like temperature and Concentrations. The crystal phase of CuCr2O4 is tetragonal having a space group is 121/amd. We calcined at 750 °C temperature. Its lattice parameters are 6.0341 and 7.7888, which is very close to the reported ones. XRD tells us about the crystal size and dislocation density of samples. Four peaks observed in UV spectra of CuCr2O4 that occurs at different regions, bandgap obtained for the parent sample is 5.02 eV, and when we doped Magnesium then the bandgap changes and becomes 4.17 eV. Similarly, SEM results show that pure copper chromite structure is tetragonal and after doping the other compounds the structure changes according to characteristics of Nanoparticles. In PL spectra four peaks are obtained one at 347 nm, 380 nm, 500 nm and the other is at 600 nm. According to Raman, shift property two peaks are obtained with different wavelengths like 1306 cm−1 and 1465 cm−1. ED’s results clearly show that copper chromites Nanoparticles successfully synthesized and when we doped Magnesium in copper chromite, the best results are observed.

Various preparation and application methods of copper chromites catalyst have recently been extensively discussed. According to all discussions, copper chromites is a versatile catalyst that not only catalyses many processes of national programmed and commercial importance, all of which are related to defense and space research, but also finds a lot of application in the most concerned worldwide, such as environmental pollution control. Copper chromites catalysts have many useful applications in the production of drugs, clean energy, and agro chemicals. Different synthesis methods are presented to prepare doped Zinc Copper chromites, demonstrating a clear understanding of the dependence of catalytic activity. This sample was created using a simple, eco-friendly sol gel method and characterized using various techniques such as EDS, SEM, UV, Raman spectroscopy, and Photoluminescence. Several parameters influence sample techniques. This sample was sintered in a furnace at 750°C for 4 hours. Zinc was successfully doped in copper chromites and emerged completely, according to EDS.

No abstract