We have successfully studied the charge transfer kinetics between carbon paste electrodes and dopamine using green synthesized rectangular monoclinic CuO nanoparticles (NPs) prepared by Alchemilla vulgaris leaves with the one-pot green synthesis method. The scanning electron microscopy (SEM) results confirmed the monoclinic structure with a particle size of around 85 nm. The investigation of thermal properties was carried out by thermogravimetric (TG) and differential thermal analysis (DTA). We also studied the electrochemical response of green synthesized CuO nanoparticles to detect Dopamine (DA) using cyclic voltammetry, which was proven to be an excellent electrocatalyst for the electro-oxidation of DA. The fabricated CuO nanoparticle modified carbon paste electrode (CMCPE) depicts fantastic selectivity, robustness, and sensitivity in analyzing DA in clinical and pharmaceutical preparations. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) orbitals of the DA were studied using positive and negative charges at the CuO modified carbon paste electrode interface. Frontier molecular orbitals of DA are plotted to understand electron transfer reactivity at the electrode interface.

The use of nonrenewable fossil fuels for energy has increased in recent decades, posing a serious threat to human life. As a result, it is critical to build environmentally friendly and low-cost reliable and renewable energy storage solutions. The supercapacitor is a future energy device because of its higher power density and outstanding cyclic stability with a quick charge and discharge process. Supercapacitors, on the other hand, have a lower energy density than regular batteries. It is well known that the electrochemical characteristic of supercapacitors is strongly dependent on electrode materials. The current review highlights advance in the TMOs for supercapacitor electrodes. In addition, the newly discovered hybrid/pseudo-supercapacitors have been discussed. Metal oxides that are employed as electrode materials are the focus of this study. The discovery of nanostructured electrode materials continues to be a major focus of supercapacitor research. To create high-performance electrode materials from a morphological standpoint, various efforts have been attempted. Lastly, we analyze the supercapacitor’s evolving trend and our perspective for the future generations of supercapacitors.

Mechanical alloying is one of the popular, simple, and easy powder metallurgy methods to prepare nanostructured high entropy alloys (HEA). HEAs are modern-day alloys that exhibit significantly improved properties and are used in many unique applications. One such application is using HEA powders for determining the methylene blue dye in wastewater using cyclic voltammetry. We have successfully synthesized the HEA powder of composition 25Fe-19Cr-19Ni-18Ti-19Mn by planetary ball mill and studied their phases, surface morphology, and particle sizes by x-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) respectively. We have fabricated the HEA-modified carbon paste electrode (HEA-MCPE) to study the electrochemical oxidation of methylene blue (MB) dye present in the wastewater. MB is a cationic dye that is toxic, and carcinogenic in high doses; generally used in textile, paper, and leather industries for coloring purposes and discharged into the water sources and thus creating a threat to aquatic animals and humans. Therefore, we must determine the MB dye in waste water regularly. Our fabricated electrode can detect MB dye in wastewater over a pH range of 6 to 7.6 with a significant current response. We have found that, the 4 mg HEA-MCPE and pH 6 are the optimal experimental conditions for achieving a higher rate of electro-oxidation of MB dye. The calculated active surface area for bare and HEA-MCPE is found to be 0.180 and 0.918 cm²respectively. We have found out that, increase in the concentration of MB from 1 mM to 5 mM increases the anodic peak current linearly due to the increased molecular interaction and the mobility of electrons between the analyte and the electrode surface.