Electrochemical Behavior of MgO-PPy-AC Composite Material for Energy Storage Devices B. Karthikeyan, K. Sakthiraj, A. Sakthivel, G. Shanmugapriya, K. Poovitha, J. Amala Ebi Jacob Chemistryselect, 2025 In the search for safer, more affordable, and environmentally friendly alternatives to Li‐ion batteries, scientists have turned their attention to multivalent ion battery systems, particularly magnesium‐ion (Mg‐ion) batteries. This study focuses on the synthesis and characterization of magnesium oxide (MgO) nanoparticles using a simple co‐precipitation method to explore their application in magnesium‐ion batteries. Characterization of the synthesized MgO nanoparticles was carried out using various techniques. X‐ray diffraction (XRD) analysis confirmed the crystalline nature and nanoscale structure of the samples, with an estimated crystallite size of approximately 46 nm. Fourier transform infrared spectroscopy (FTIR) identified the presence of Mg‐O stretching vibrations, whereas ultraviolet–visible‐near infrared (UV–vis–NIR) spectroscopy determined the optical band gap to be 5.07 eV. To enhance electrochemical performance, a composite material was fabricated by incorporating MgO nanoparticles with polypyrrole (PPy) and activated charcoal (AC). Cyclic voltammetry (CV) analysis revealed a quasi‐reversible redox process in the composite, with a peak specific capacitance of 713 F g −1 at a scan rate of 25 mV s −1 . Electrochemical impedance spectroscopy further demonstrated the dielectric behavior of MgO nanoparticles, reinforcing their potential in charge storage and ion transport. Overall, the findings of this research highlight the exceptional electrochemical properties of the MgO‐PPy‐AC composite, making it a promising electrode material for next‐generation energy storage devices, such as batteries and supercapacitors.
Electrochemical Performance of Magnesium-Doped Strontium Carbonate Nanoparticles for Energy Storage Applications K. Sakthiraj, B. Karthikeyan, M. Hema Russian Journal of Electrochemistry, 2025 Abstract This work presents a comprehensive study of the synthesis, structural, and electrochemical characterization of pure and magnesium-doped strontium carbonate (SrCO3) nanoparticles. Powder X-ray diffraction (XRD) analysis confirmed the orthorhombic phase of SrCO3 and the presence of MgO in the doped samples. Crystallite sizes and lattice strains were determined using the Debye–Scherrer and Williamson–Hall equations, revealing compressive strain in pure SrCO3 and significant structural changes with Mg doping. Scanning electron microscopy (SEM) displayed rod-like SrCO3 particles, which diminished in size with increased Mg content. Energy-dispersive X-ray spectroscopy (EDAX) confirmed the elemental composition, showing enhanced oxygen content with Mg doping. Raman spectroscopy identified shifts in vibrational modes due to Mg addition. Electrochemical performance, investigated via cyclic voltammetry (CV), revealed that lower Mg doping (3%) enhanced specific capacitance at low scan rates and current densities. Electrochemical impedance spectroscopy (EIS) showed increased resistive behavior and capacitive properties with higher Mg content, while open circuit potential (OCP) analysis indicated improved electrochemical stability in Mg-doped samples. The results demonstrate the potential of Mg-doped SrCO3 for applications requiring enhanced electrochemical performance.
Structural, morphological, and electrochemical studies of Mg2SiO4-Pr6O11 nanocomposite for energy storage applications B Karthikeyan, K Sakthiraj, A Sakthivel Physica Scripta, 2023 Owing to not only the high demand in the development of new materials for the energy storage applications but also the high abundance of magnesium orthosilicate (Mg2SiO4) belonging to olivine group of minerals in Earth, magnesium orthosilicate (called as MOS) nanoparticle and magnesium orthosilicate–praseodymium oxide (Mg2SiO4–Pr6O11) (MOS-PO) nanocomposite have been chosen to explore mainly their electrochemical characteristics. The MOS nanoparticle and MOS-PO nanocomposite were synthesized using sol-gel method. The characterization techniques such as x-ray diffraction (XRD), Scanning Electron Microscopy (SEM), energy dispersive x-ray (EDX) spectroscopy, Zeta potential analyzer, and Cyclic Voltammetry (CV) were used to investigate the structural, morphological, and electrochemical properties of the prepared samples. Using Scherrer’s equation, phase identification was performed for the samples of MOS nanoparticle and MOS-PO nanocomposite with crystallite sizes 43 nm and 52 nm, respectively. The respective average particle sizes of 39 nm and 50 nm were observed for MOS nanoparticle and MOS-PO nanocomposite, using SEM images, and these values along with the images revealed the formation of spherical nanoparticles along with some agglomerates. The Zeta potential of the samples was calculated to analyze the stability of the nanoparticles. The electrochemical characterization was performed using the sample coated Mg foil as the working electrode and 0.5 M of KOH solution as the electrolyte, with the help of cyclic voltametric technique. The CV analysis was conducted ranging from 1.5 to −1.5 V at various scan rates of 25, 50, 100, 200, and 300 mVs−1. For MOS-PO nanocomposite, the maximum specific capacitance of 1812 Fg−1 was observed at a scan rate of 25 mVs−1. The results showed the possibility of the usage of MOS-PO nanocomposite material in the application of energy storage devices.
Investigation of indium trihydride molecule and its clusters using density functional theory for semiconductor application B. Karthikeyan, K. Sakthiraj, P. Senthilkumar Acta Physica Polonica A, 2021 It is widely known that few metal hydrides are potential candidates as atom sources for organo-metallic vapor phase epitaxial growth of III-V semiconductor layers. For such an application, it is important to know the structure, bond lengths, bond angles and other molecular properties of metal hydrides such as BHn, AlHn, GaHn, AsHn, InHn and SbHn. In this view of semiconductor application, indium trihydride clusters (InH3)n=1-3 have been chosen in the present study and clusters of InH3 molecules, i.e., InH3, In2H6 and In3H9, have been investigated using density functional theory in conjunction with the B3LYP-LANL2dZ basis set which is the most popular effective core potential for the computations on metal containing systems. Various parameters including zero point vibrational energy, thermal energy, specific heat, entropy, heat of formation, vibrational frequencies and their intensities, etc., were derived. The infrared spectral features of indane (InH3), diindane (In2H6) and triindane (In3H9) were compared with the already reported set of data. It was predicted based on the results obtained in the present study that the stability of the In3H9 molecule was possible, since no imaginary frequencies in the IR spectra and favourable heats of formation were obtained. The results obtained in the present study gave a new perspective of the (InH3)n=1,2,3 material.
