High-performance symmetric supercapacitor; nanoflower-like NiCo2O4//NiCo2O4 thin films synthesized by simple and highly stable chemical method

Experimental and computational approach of zirconium and chitosan doped NiCo2O4 nanorods served as dye degrader and bactericidal action

Different concentrations of zirconium with a fixed quantity (4 wt%) of chitosan (CS) doped nickel cobaltite (NiCo2O4) nanorods were synthesized using a co-precipitation approach. This cutting-edge research explores the cooperative effect of Zr-doped CS-NiCo2O4 to degrade the Eriochrome black T (EBT) and investigates potent antibacterial activity against Staphylococcus aureus (S. aureus). Advanced characterization techniques were conducted to analyze structural textures, morphological analysis, and optical characteristics of synthesized materials. XRD pattern unveiled the spinal cubic structure of NiCo2O4, incorporating Zr and CS peak shifted to a lower 2θ value. UV-Vis spectroscopy revealed the absorption range increased with CS and the same trend was observed upon Zr, showing a decrease in bandgap energy (Eg) from 2.55 to 2.4 eV. The optimal photocatalytic efficacy of doped NiCo2O4 within the basic medium was around 96.26 %, and bactericidal efficacy was examined against S. aureus, revealing a remarkable inhibition zone (5.95 mm).

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.

SILAR Deposition of Metal Oxide Nanostructured Films

Methods for the fabrication of thin films with well controlled structure and properties are of great importance for the development of functional devices for a large range of applications. SILAR, the acronym for Successive Ionic Layer Adsorption and Reaction, is an evolution and combination of two other deposition methods, the Atomic Layer Deposition and Chemical Bath Deposition. Due to a relative simplicity and low cost, this method has gained increasing interest in the scientific community. There are, however, several aspects related to the influence of the many parameters involved, which deserve further deepening. In this review article, the basis of the method, its application to the fabrication of thin films, the importance of experimental parameters, and some recent advances in the application of oxide films are reviewed. At first the fundamental theoretical bases and experimental concepts of SILAR are discussed. Then, the fabrication of chalcogenides and metal oxides is reviewed, with special emphasis to metal oxides, trying to extract general information on the effect of experimental parameters on structural, morphological and functional properties. Finally, recent advances in the application of oxide films prepared by SILAR are described, focusing on supercapacitors, transparent electrodes, solar cells, and photoelectrochemical devices.

Controllable synthesis of ZIF-derived NixCo3-xO4 nanotube array hierarchical structures based on self-assembly for high-performance hybrid alkaline batteries

In this study, a novel NixCo3-xO4 nanotube array hierarchical structure derived from zeolitic imidazolate frameworks (ZIFs) is grown on Ni foam (NixCo3-xO4 NAHS/Ni foam) using the template-assisted and self-assembly approach for a high-performance hybrid energy storage device in alkaline solution. The material characteristics of the resultant samples were characterized by XPS, XRD, ICP, SEM, TEM and BET. Due to the unique hollow structure with a large specific surface area and the exposure of large active sites originating from ZIFs, the optimal NixCo3-xO4 NAHS/Ni foam exhibits substantially enhanced electrochemical properties. The NixCo3-xO4 NAHS/Ni foam directly acts as an electrode, which provides an excellent specific capacity of 290.48 mA h g-1 at 1 A g-1. Subsequently, the corresponding hybrid alkaline batteries that consist of NixCo3-xO4 NAHS/Ni foam and carbon materials display a highly satisfactory specific capacity of 54.94 mA h g-1 at 1 A g-1, a satisfactory long-term stability of 85.47% after 2000 cycles, a maximum energy density of 43.95 W h kg-1 and a power density of 8000 W kg-1. This work combines the design of the electronic structure with the optimization of composition, and provides a reference for the application of hybrid rechargeable alkaline batteries (RABs).

Reagent-assisted hydrothermal synthesis of NiCo2O4 nanomaterials as electrodes for high-performance asymmetric supercapacitors

Spinel nickel cobaltate nanoneedle arrays in situ synthesized by a CTAB assisted hydrothermal method show an energy density of 22.5 W h kg⁻¹ at 800 W kg⁻¹.

Electrochemically Synthesized Nanoflowers to Nanosphere-Like NiCuSe2 Thin Films for Efficient Supercapacitor Application

Developing efficient electrochemically active nanostructures from Earth-abundant elements has gained significant interest in recent years. Among different transition metals, nickel and copper are abundant electrocatalysts for energy-storage applications. Nickel–copper selenide (NiCuSe2) nanostructures were prepared on a stainless-steel mesh with a cost-effective, simple, and versatile electrodeposition method for supercapacitor applications. The change effect in the bath concentration of nickel and copper altered the structural and electrochemical properties of NiCuSe2 electrode. X-ray diffraction (XRD) patterns confirmed the pure phase of ternary NiCuSe2 thin films with a cubic crystal structure. The surface morphology of NiCuSe2 was tuned by nickel and copper from spherical porous nanoflowers, nanoplates, nanocubes, and nanosphere-like nanostructures deposited on the stainless-steel mesh. The electrochemical performance of the electrodeposited NiCuSe2 was investigated in alkaline 1 M KOH electrolyte. The synergetic effect of bimetallic nickel and copper with the selenide electrode showed superior specific capacity of about 42.46 mAh g−1 at 10 mV s−1 along with reasonable cycling stability.

Nickel-Graphene Nanoplatelet Deposited on Carbon Fiber as Binder-Free Electrode for Electrochemical Supercapacitor Application

A binder-free process for the electrode preparation for supercapacitor application was suggested by drop casting graphene nanoplatelets on a carbon fiber (GnP@CF) followed by electrodeposition of Ni nanoparticles (NPs). The microstructure of the electrode showed that Ni was homogeneously distributed over the surface of the GnP@CF. XRD analysis confirmed the cubic structure of metallic Ni NPs. The Ni-GnP@CF electrode showed excellent pseudocapacitive behavior in alkaline solution by exhibiting a specific capacitance of 480 F/g at 1.0 A/g, while it was 375 F/g for Ni@CF. The low value of series resistance of Ni-GnP@CF (1 Ω) was attributed to the high capacitance. The enhanced capacitance of the electrode could be correlated to the highly nanoporous structure of the composite material, synergetic effect of the electrical double layer charge-storage properties of graphene, and the pseudocapacitive nature of Ni NPs.