Hydrothermal synthesis of CuO@MnO2 on nitrogen-doped multiwalled carbon nanotube composite electrodes for supercapacitor applications.

Nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs) have been used to fabricate nanostructured materials for various energy devices, such as supercapacitors, sensors, batteries, and electrocatalysts. Nitrogen-doped carbon-based electrodes have been widely used to improve supercapacitor applications via various chemical approaches. Based on previous studies, CuO@MnO2 and CuO@MnO2/N-MWCNT composites were synthesized using a sonication-supported hydrothermal reaction process to evaluate their supercapacitor properties. The structural and morphological properties of the synthesized composite materials were characterized via Raman spectroscopy, XRD, SEM, and SEM-EDX, and the morphological properties of the composite materials were confirmed by the nanostructured composite at the nanometer scale. The CuO@MnO2 and CuO@MnO2/N-MWCNT composite electrodes were fabricated in a three-electrode configuration, and electrochemical analysis was performed via CV, GCD, and EIS. The composite electrodes exhibited the specific capacitance of ~ 184 F g-1 at 0.5 A g-1 in the presence of a 5 M KOH electrolyte for the three-electrode supercapacitor application. Furthermore, it exhibited significantly improved specific capacitances and excellent cycling stability up to 5000 GCD cycles, with a 98.5% capacity retention.

A Novel Synthesized 1D Nanobelt-like Cobalt Phosphate Electrode Material for Excellent Supercapacitor Applications.

In the present report, we synthesized highly porous 1D nanobelt-like cobalt phosphate (Co2P2O7) materials using a hydrothermal method for supercapacitor (SC) applications. The physicochemical and electrochemical properties of the synthesized 1D nanobelt-like Co2P2O7 were investigated using X-ray diffraction (XRD), X-ray photoelectron (XPS) spectroscopy, and scanning electron microscopy (SEM). The surface morphology results indicated that the deposition temperatures affected the growth of the 1D nanobelts. The SEM revealed a significant change in morphological results of Co2P2O7 material prepared at 150 °C deposition temperature. The 1D Co2P2O7 nanobelt-like nanostructures provided higher electrochemical properties, because the resulting empty space promotes faster ion transfer and improves cycling stability. Moreover, the electrochemical performance indicates that the 1D nanobelt-like Co2P2O7 electrode deposited at 150 °C deposition temperature shows the maximum specific capacitance (Cs). The Co2P2O7 electrode prepared at a deposition temperature 150 °C provided maximum Cs of 1766 F g-1 at a lower scan rate of 5 mV s-1 in a 1 M KOH electrolyte. In addition, an asymmetric hybrid Co2P2O7//AC supercapacitor device exhibited the highest Cs of 266 F g-1, with an excellent energy density of 83.16 Wh kg-1, and a power density of 9.35 kW kg-1. Additionally, cycling stability results indicate that the 1D nanobelt-like Co2P2O7 material is a better option for the electrochemical energy storage application.

Ultrasonication-mediated nitrogen-doped multiwalled carbon nanotubes involving carboxy methylcellulose composite for solid-state supercapacitor applications.

In this study, a novel nanohybrid composite containing nitrogen-doped multiwalled carbon nanotubes/carboxymethylcellulose (N-MWCNT/CMC) was synthesized for supercapacitor applications. The synthesized composite materials were subjected to an ultrasonication-mediated solvothermal hydrothermal reaction. The synthesized nanohybrid composite electrode material was characterized using analytical methods to confirm its structure and morphology. The electrochemical properties of the composite electrode were investigated using cyclic voltammetry (CV), galvanic charge-discharge, and electrochemical impedance spectroscopy (EIS) using a 3 M KOH electrolyte. The fabricated composite material exhibited unique electrochemical properties by delivering a maximum specific capacitance of approximately 274 F g-1 at a current density of 2 A g-1. The composite electrode displayed high cycling stability of 96% after 4000 cycles at 2 A g-1, indicating that it is favorable for supercapacitor applications.

Nanorods to hexagonal nanosheets of CuO-doped manganese oxide nanostructures for higher electrochemical supercapacitor performance.

In this work, the extraordinary properties of CuO addition on the morphology and supercapacitive performance of Mn2O3 electrodes were demonstrated. Concisely, CuO/Mn2O3 thin films were prepared by an easy and inexpensive successive ionic layer adsorption and reaction (SILAR) method. The prepared thin films were characterized by various sophisticated physiochemical systems. The results demonstrated formation of Mn2O3 thin films with noteworthy morphological alteration upon introduction of CuO. Furthermore, a significant effect of CuO introduction was observed on the electrocatalytic properties of the nanostructured Mn2O3 electrodes. At 3% CuO doping, the Mn2O3 electrodes displayed the maximum specific capacitance owing to formation of nanoplate-like structures. The enhanced specific capacitance attained for 3% CuO doping in the Mn2O3 electrode was 500 F/g at 5 mV/s in a 3 M KOH electrolyte. All results confirmed the plausible potential of the CuO/Mn2O3 electrode for supercapacitor applications.

Using chemical bath deposition to create nanosheet-like CuO electrodes for supercapacitor applications.

We report the effect of ionic liquids on chemically synthesized hierarchical-like copper oxide (CuO) thin films for supercapacitor applications. Concisely, the CuO thin films were deposited via chemical bath deposition (CBD) using 2-dimethylimidazolium chloride [HPDMIM(C1)], 1-(2',3'-dihydroxypropyl)-3-methylimidazolium chloride [DHPMIM(C1)], and N-(3-methyl-2-oxopropyl)pyridine chloride [MOCPP(C1)] ionic liquid solvents. The effects of the ionic liquid solvents on the morphological evolution of the as-prepared films were analyzed, and electrochemical properties were investigated. The highest specific capacitance was achieved for the electrode with a nanosheet-like structure produced by functionalization with the HPDMIM(C1) ionic liquid. The maximum specific capacitance achieved for the HPDMIM(C1):CuO hybrid electrode was 464 F g-1 at 5 mV s-1 in a 1 M Na2SO4 electrolyte. Thus, our findings, in addition to the stability of the HPDMIM(C1):CuO, indicate that it is a candidate for energy-storage applications.

Porous materials of nitrogen doped graphene oxide@SnO2 electrode for capable supercapacitor application.

The porous materials of SnO2@NGO composite was synthesized by thermal reduction process at 550 °C in presence ammonia and urea as catalyst. In this process, the higher electrostatic attraction between the SnO2@NGO nanoparticles were anchored via thermal reduction reaction. These synthesized SnO2@ NGO composites were confirmed by Raman, XRD, XPS, HR-TEM, and EDX results. The SnO2 nanoparticles were anchored in the NGO composite in the controlled nanometer scale proved by FE-TEM and BET analysis. The SnO2@NGO composite was used to study the electrochemical properties of CV, GCD, and EIS analysis for supercapacitor application. The electrochemical properties of SnO2@NGO exhibited the specific capacitance (~378 F/g at a current density of 4 A/g) and increasing the cycle stability up to 5000 cycles. Therefore, the electrochemical results of SnO2@NGO composite could be promising for high-performance supercapacitor applications.

Novel approach to synthesize NiCo2S4 composite for high-performance supercapacitor application with different molar ratio of Ni and Co.

Here, we developed a new approach to synthesize NiCo2S4 thin films for supercapacitor application using the successive ionic layer adsorption and reaction (SILAR) method on Ni mesh with different molar ratios of Ni and Co precursors. The five different NiCo2S4 electrodes affect the electrochemical performance of the supercapacitor. The NiCo2S4 thin films demonstrate superior supercapacitance performance with a significantly higher specific capacitance of 1427 F g-1 at a scan rate of 20 mV s-1. These results indicate that ternary NiCo2S4 thin films are more effective electrodes compared to binary metal oxides and metal sulfides.

Synthesis and characterization of chitosan-TiO2:Cu nanocomposite and their enhanced antimicrobial activity with visible light.

In the present investigation, novel strategy for the preparation of hybrid nanocomposite containing organic polymer (Chitosan) and inorganic (TiO2:Cu) nanoparticles (NPs) has been developed and demonstrated its biomedical application. The sol-gel and ultra-sonication method assisted for the preparation of uniformly distributed Chitosan-TiO2:Cu (CS-CT) nanocomposite. The structural properties of prepared CS-CT nanocomposite were studied by XRD and FTIR techniques. The XPS was used to estimate elemental composition of the nanocomposite. Thermal properties were studied using TGA. TEM and SEM analysis showed the non-spherical nature of NPs with the average mean diameter 16nm. The optical properties were analyzed with UV-vis diffuse reflectance spectroscopy to confirm optical absorption in the visible region of light. Where CS-CT showed 200% enhanced light mediated photocatalytic antimicrobial activity against microorganism (Escherichia coli and Staphylococcus aureus) as compared with control. The antimicrobial activity of CS-CT nanocomposite in presence of light is found to be enhanced than that of its components, this is due to synergistic effect of organic and inorganic material complimenting each other's activity. The OH radicals release studied by PL spectroscopy on the surface of nanocomposite was used to examine antibacterial activity. Cytotoxicity assessment of CS-CT on human fibroblast cells was performed by MTT assay.

Synthesis, characterization and biocompatibility of chitosan functionalized superparamagnetic nanoparticles for heat activated curing of cancer cells.

Surface functionalization, colloidal stability and biocompatibility of magnetic nanoparticles are crucial for their biological applications. Here, we report a synthetic approach for the direct preparation of superparamagnetic nanoparticles consisting of a perovskite LSMO core modified with a covalently linked chitosan shell that provides colloidal stability in aqueous solutions for cancer hyperthermia therapy. The characterization of the core-shell nanostructure using Fourier transform infrared spectroscopy; thermo-gravimetric analysis to assess the chemical bonding of chitosan to nanoparticles; field-emission scanning electron microscopy and transmission electron microscopy for its size and coating efficiency estimation; and magnetic measurement for their magnetization properties was performed. Zeta potential and light scattering studies of the core shell revealed it to possess good colloidal stability. Confocal microscopy and MTT assay are performed for qualitative and quantitative measurement of cell viability and biocompatibility. In depth cell morphology and biocompatibility is evaluated by using multiple-staining of different dyes. The magnetic@chitosan nanostructure system is found to be biocompatible up to 48 h with 80% cell viability. Finally, an in vitro cancer hyperthermia study is done on the MCF7 cell line. During in vitro hyperthermia treatment of cancer cells, cell viability is reduced upto 40% within 120 min with chitosan coated nanoparticles. Our results demonstrate that this simplified and facile synthesis strategy shows potential for designing a colloidal stable state and biocompatible core shell nanostructures for cancer hyperthermia therapy.

Structured superparamagnetic nanoparticles for high performance mediator of magnetic fluid hyperthermia: synthesis, colloidal stability and biocompatibility evaluation.

Core-shell structures with magnetic core and metal/polymer shell provide a new opportunity for constructing highly efficient mediator for magnetic fluid hyperthermia. Herein, a facile method is described for the synthesis of superparamagnetic LSMO@Pluronic F127 core-shell nanoparticles. Initially, the surface of the LSMO nanoparticles is functionalized with oleic acid and the polymeric shell formation is achieved through hydrophobic interactions with oleic acid. Each step is optimized to get good dispersion and less aggregation. This methodology results into core-shell formation, of average diameter less than 40 nm, which was stable under physiological conditions. After making a core-shell formulation, a significant increase of specific absorption rate (up to 300%) has been achieved with variation of the magnetization (<20%). Furthermore, this high heating capacity can be maintained in various simulated physiological conditions. The observed specific absorption rate is almost higher than Fe3O4. MTT assay is used to evaluate the toxicity of bare and core-shell MNPs. The mechanism of cell death by necrosis and apoptosis is studied with sequential staining of acridine orange and ethidium bromide using fluorescence and confocal microscopy. The present work reports a facile method for the synthesis of core-shell structure which significantly improves SAR and biocompatibility of bare LSMO MNPs, indicating potential application for hyperthermia.