Recent Development on Transition Metal Oxides-Based Core-Shell Structures for Boosted Energy Density Supercapacitors.

In recent years, nanomaterials exploration and synthesis have played a crucial role in advancing energy storage research, particularly in supercapacitor development. Researchers have diversified materials, including metal oxides, chalcogenides, and composites, as well as carbon materials, to enhance energy and power density. Balancing energy density with electrochemical stability remains challenging, driving intensified efforts in advancing electrode materials. This review focuses on recent progress in designing and synthesizing core-shell materials tailored for supercapacitors. The core-shell architecture offers advantages such as increased surface area, redox active sites, electrical conductivity, ion diffusion kinetics, specific capacitance, and cyclability. The review explores the impact of core and shell materials, specifically transition metal oxides (TMOs), on supercapacitor electrochemical behavior. Metal oxide choices, such as cobalt oxide as a preferred core and manganese oxide as a shell, are discussed. The review also highlights characterization techniques for assessing structural, morphological, and electrochemical properties of core-shell materials. Overall, it provides a comprehensive overview of ongoing TMOs-based core-shell material research for supercapacitors, showcasing their potential to enhance energy storage for applications ranging from gadgets to electric vehicles. The review outlines existing challenges and future opportunities in evolving TMOs-based core-shell materials for supercapacitor advancements, holding promise for high-efficiency energy storage devices.

Natural Biowaste Derived Fluorescent Carbon Quantum Dots: Synthesis, Characterization and Biocompatibility Study.

In this present study, a straightforward and affordable method for the environmentally safe synthesis of carbon quantum dots (CQDs) by employing human hair as the carbon source without any need of chemicals was synthesized. CQDs obtained from human hair was further functionalized with Poly-L-Lysine to form PLLCQDs. The synthesized PLLCQDs was demonstrated numerous advantageous characteristics like strong fluorescence intensity, superior photostability, and outstanding water solubility. Various physicochemical characterization was employed to confirm successful formation of PLLCQDs including UV-vis Spectroscopy, Fluorescence Spectroscopy, Fourier Transform Infrared (FTIR) Spectroscopy, Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM). The size of synthesized PLLCQDs is 3 nm. The resultant PLLCQDs exhibited strong blue emission with a quantum yield of 28%. Under UV light, the synthesized PLLCQDs emit blue (at 365nm) fluorescence. The optimization of synthesis parameters including synthesis method, effect of reaction temperature, effect of reaction time and effect of reaction concentration have a significant impact on the quality and quantity of synthesized PLLCQDs, as well as their properties and applications. The effect of pH and UV radiation on synthesized PLLCQDs exhibited excellent photo and chemical stability. The cytotoxicity of bulk system (Hair precursor) and PLLCQDs was evaluated using fibroblast cell line (L929). The cell viabilities of 99.47% was obtained from L929 cells using MTT assay and it can applicably function as agents for cell labelling as a good bioimaging probe.

Synergistic effect of Fe and BiOCl in enhancing electrocatalytic performance for oxygen evolution reaction.

Fe was added to bismuth oxychloride (BiOCl) to improve its oxygen evolution reaction(OER) catalytic activity. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), EDS, and X-ray photoelectron spectroscopy (XPS) were used to analyze the material that was produced. Many electrochemical techniques, including linear sweep voltammetry (LSV), Mott Schottky, and electrochemical impedance spectroscopy (EIS), were used to conduct the electrochemical studies of Fe doped BiOCl. Fe doped BiOCl exhibited enhanced catalytic performance compared to pristine BiOCl. The best performance was observed for 0.75 M Fe doped BiOCl sample. It recorded lowest overpotential of 354 mV @ 10 mA cm-2 and Tafel slope of 167 mV dec-1. The synergistic effect of Fe doping from structural, chemical and catalytic perspective has been analyzed and presented.

Green Synthesis of Fluorescent Carbon Dots from Annona squamosa Leaves: Optical and Structural Properties with Bactericidal, Anti-inflammatory, Anti-angiogenesis Applications.

A hydrothermal method was employed for green synthesis of fluorescent carbon dots (GCDs) from Annona squamosa leaves. The synthesized GCDs were confirmed by microscopic and spectroscopic techniques such as: High Resolution Transmission Electron Microscopy (HR-TEM), Atomic Force Microscopy (AFM), UV-Vis spectrometry, Fluorescence spectrometry, X-Photoelectron Spectroscopy (XPS), X-ray Diffraction spectroscopy (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). The produced GCDs had shown multiple properties, including massive antibacterial activity at concentration 200 µg/ml. The stabilization of human red blood cells served as a method to assess the anti-inflammatory activity. We also looked at how GCDs affected the angiogenesis process. The density of blood vessels was significantly decreased after treatment with GCDs, according to the results of the Chorio-Allantoic Membrane assay (p < 0.05). As per the study prepared GCDs from fallen leaves of Annona squamosa have multifunctional applications.