Sulfur and phosphorus co-doped nickel-cobalt layered double hydroxides for enhancing electrochemical reactivity and supercapacitor performance.

Layered double hydroxides (LDHs) have drawn significant interest as emerging active materials for advanced energy storage devices; however, their low electric and ionic conductivity limit their applications. In this study, we report sulfur (S) and phosphorus (P) co-doped NiCo LDH nanoarrays prepared a facile phosphor-sulfurization process to impart diverse co-doping effects. Combining the benefits of their unique hierarchical structure and reduced charge transfer resistance, the S and P co-doped NiCo LDH (NiCo LDH-SP) nanoarrays realize faster and more efficient redox reactions and achieve enhanced surface reactivity, thereby resulting in a performance superior to that of pristine NiCo LDH.

Bifunctional Microwave-Assisted Molybdenum-Complex Carbon Sponge Production for Supercapacitor and Water-Splitting Applications.

The synthesis of dual-function molybdenum (Mo)-complex carbonous sponges is reported for elucidating their utilization as positive and negative electrodes in electrochemical devices and their applicability to the active oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in electrocatalytic devices. Molybdenum (Mo)-coordinated polyvinyl alcohol gel is converted into a porous Mo-complex nitrogen-rich carbonous sponge (MNCS) via microwave and low-temperature-annealing processes as a positive electrode. This MNCS was further thermally treated at a higher temperature to prepare a more carbonized Mo-complex N-doped carbon sponge (cMNCS) as a negative electrode.

Synthesis of nickel-copper composite with controllable nanostructure through facile solvent control as positive electrode for high-performance supercapacitors.

The surface characteristics of electrodes vary depending on the solvent used. Furthermore, electrochemical performance varies depending on the surface morphology of the electrode. In this study, we grew 3D binary NiCu-based composites on Ni foam, via a binder-free hydrothermal method, for use as a cathode in high-performance supercapacitors.

Room-temperature chemical synthesis of 3-D dandelion-type nickel chloride (NiCl@NiF) supercapattery nanostructured materials.

A simple, room-temperature operable, glycerol-supported single beaker-inspired, and binder-free soft-chemical protocol has been developed to synthesize 3-D dandelion flower-type nickel chloride (NiCl) supercapattery (supercapacitor + battery) nanostructured electrode material from solid 3-D nickel-foam (NiF). The dandelion flower-type NiCl@NiF labeled as B electrode, demonstrates a battery-type electrochemical performance as obtained 1551 F·g specific capacitance (SC) and 95% cyclability over 50,000 cycles is higher than that of a setaria viridis-type NiCl@NiF electrode, prepared without glycerol labeled as A electrode. As a commercial market product, assembled NiCl@NiF@ (cathode)// BiMoO (anode) pouch-type asymmetric supercapacitor energy storage device demonstrates moderate energy density and power density (28 Wh·kg and 845 W·kg).

NiF Nanorod Arrays for Supercapattery Applications.

A electrode for energy storage cells is possible directly on Ni foam, using a simple reduction process to form NiF nanorod arrays (NA). We demonstrate NiF@Ni NA for a symmetric electrochemical supercapattery electrode. With an areal specific capacitance of 51 F cm at 0.

Room-temperature synthesis and CO-gas sensitivity of bismuth oxide nanosensors.

Room-temperature (27 °C) synthesis and carbon dioxide (CO)-gas-sensor applications of bismuth oxide (BiO) nanosensors obtained a direct and superfast chemical-bath-deposition method (CBD) with different surface areas and structures, , crystallinities and morphologies including a woollen globe, nanosheet, rose-type, and spongy square plate on a glass substrate, are reported. Moprhologies of the BiO nanosensors are tuned through polyethylene glycol, ethylene glycol, and ammonium fluoride surfactants. The crystal structure, type of crystallinity, and surface appearance are determined from the X-ray diffraction patterns, X-ray photoelectron spectroscopy spectra, and high-resolution transmission electron microscopy images.

Chemically grown bismuth-oxy-iodide (BiOI/BiI) nanostructure for high performance battery-type supercapacitor electrodes.

A dual phase bismuth oxyiodide (BiOI/Bi9I2) nanostructure battery type supercapacitor electrode is synthesized using chemical bath deposition (CBD) and the capacitance and energy/power density (ED/PD) reported. The supercapacitor electrode BiOI/Bi9I2 exhibited a specific capacitance of 515.5 F g-1 (capacity value 143 mA h g-1) at a current density of 2 A g-1, with 80% of the original capacitance retained, even at a high current density of 4 A g-1 over 5000 cycles.

Asymmetric faradaic assembly of BiO and MnO for a high-performance hybrid electrochemical energy storage device.

In the current study, we have explored the coupling of BiO negative electrode and MnO positive electrode materials as an asymmetric faradaic assembly for a high-performance hybrid electrochemical energy storage device (HEESD). Aiming at a low-cost device, both the electrodes have been synthesized by a simple, scalable, and cost-effective chemical synthesis method. After their requisite structure-morphological confirmation and correlation, these electrodes were separately examined for their electrochemical performance in a three-electrode configuration.

Facile Chemical Synthesis and Potential Supercapattery Energy Storage Application of Hydrangea-type BiMoO.

Soft chemical synthesis is used to obtain a hydrangea-type bismuth molybdate (BiMoO) supercapattery electrode that demonstrates considerable energy/power density and cycling life. Structure and morphology studies, initially, reveal a phase-pure polycrystalline and hydrangea-type surface appearance for BiMoO, which upon testing in an electrochemical energy storage system displays supercapattery behavior, a combination of a supercapacitor and a battery. From the power law, an applied-potential-dependent charge storage mechanism is established for the BiMoO electrode material.

Electrocatalytic Water Splitting through the Ni S Self-Grown Superstructures Obtained via a Wet Chemical Sulfurization Process.

We report water-splitting application of chemically stable self-grown nickel sulfide (Ni S ) electrocatalysts of different nanostructures including rods, flakes, buds, petals, etc., synthesized by a hydrothermal method on a three-dimensional Ni foam (NiF) in the presence of different sulfur-ion precursors, e.g.

Sulphur Source-Inspired Self-Grown 3D Ni S Nanostructures and Their Electrochemical Supercapacitors.

Sulphur source-inspired self-grown polycrystalline and mesoporous nickel sulfide (Ni S ) superstructures with vertically aligned nanomorphologies viz. rods, flakes, buds, and petals, synthesized at elevated temperatures and moderate pressures by a facile one-pot hydrothermal method on a three-dimensional Ni foam demonstrate remarkable areal specific capacitances of 7152, 4835, and 2160 F cm at current densities of 1, 2, and 5 mA cm, respectively, with a cycling stability of 94% for a battery-type electrochemical supercapacitor when used as an electrode material in a supercapacitor. The Ni S //BiO asymmetric supercapacitor assembly exhibits an energy density of 41 W h·kg at a power density of 1399 W kg for 1 A g and was used in a three-cell series combination to operate a "GFHIM" display panel (our research institute name, Global Frontier R & D Center for Hybrid Interface Materials) composed of nearly 50 differently colored light-emitting diodes with high intensity in 1 M KOH water-alkali electrolyte.

Architecturally Robust Graphene-Encapsulated MXene TiCT @Polyaniline Composite for High-Performance Pouch-Type Asymmetric Supercapacitor.

A harmonized three-component composite system which preserves the characteristics of individual components is of interest in the field of energy storage. Here, we present a graphene-encapsulated MXene TiCT @polyaniline composite (GMP) material realized in a systematically stable configuration with different ternary nanomaterials for supercapacitor electrodes. Due to the different ζ-potentials in a high-pH solution, chemically converted graphene (negatively charged) is thoroughly unfolded to allow full encapsulation, but the MXene TiCT @polyaniline composite with a low positive ζ-potential is easily attracted toward a counter-charged substance.

Seawater electrolyte-mediated high volumetric MXene-based electrochemical symmetric supercapacitors.

The structure and morphology of titanium carbide (Ti3C2Tx) MXene, a new class of two dimensional (2D) materials, are investigated and reported. Ti3AlC2 MAX, treated with a hydrofluoric acid etching process, is used as a promising electrode material for electrochemical supercapacitor studies. The electrochemical supercapacitor performance of Ti3C2Tx as a negatrode in a natural seawater electrolyte solution, tested in a three-electrode system, demonstrated a specific capacitance of 67.

Metal-free heterogeneous and mesoporous biogenic graphene-oxide nanoparticle-catalyzed synthesis of bioactive benzylpyrazolyl coumarin derivatives.

We report the preparation of graphene oxide nanoparticles (GONPs), a metal-free, heterogeneous, non-toxic, reusable and mesoporous green-(acid)-catalyst obtained by sugar carbonization through a micro-wave chemical synthesis method for the synthesis of bio-active benzylpyrazolyl coumarin derivatives (BCDs) under thermal conditions (50 °C) in ethanol solvent. The obtained products were purified by re-crystallization from ethanol, assuring usability of GONPs in multicomponent reactions (MCRs) that could find wide application in the synthesis of a variety of biologically potent molecules of therapeutic significance.

Polycrystalline and Mesoporous 3-D BiO Nanostructured Negatrodes for High-Energy and Power-Asymmetric Supercapacitors: Superfast Room-Temperature Direct Wet Chemical Growth.

Superfast (≤10 min) room-temperature (300 K) chemical synthesis of three-dimensional (3-D) polycrystalline and mesoporous bismuth(III) oxide (BiO) nanostructured negatrode (as an abbreviation of negative electrode) materials, viz., coconut shell, marigold, honey nest cross section and rose with different surface areas, charge transfer resistances, and electrochemical performances essential for energy storage, harvesting, and even catalysis devices, are directly grown onto Ni foam without and with poly(ethylene glycol), ethylene glycol, and ammonium fluoride surfactants, respectively. Smaller diffusion lengths, caused by the involvement of irregular crevices, allow electrolyte ions to infiltrate deeply, increasing the utility of inner active sites for the following electrochemical performance.

Tailoring the morphology followed by the electrochemical performance of NiMn-LDH nanosheet arrays through controlled Co-doping for high-energy and power asymmetric supercapacitors.

Herein, we tailor the surface morphology of nickel-manganese-layered double hydroxide (NiMn-LDH) nanostructures on 3D nickel-foam via a step-wise cobalt (Co)-doping hydrothermal chemical process. At the 10% optimum level of Co-doping, we noticed a thriving tuned morphological pattern of NiMn-LDH nanostructures (NiCoMn-LDH (10%)) in terms of the porosity of the nanosheet (NS) arrays which not only improves the rate capability as well as cycling stability, but also demonstrates nearly two-fold specific capacitance enhancement compared to Co-free and other NiCoMn-LDH electrodes with a half-cell configuration in 3 M KOH, suggesting that Co-doping is indispensable for improving the electrochemical performance of NiMn-LDH electrodes. Moreover, when this high performing NiCoMn-LDH (10%) electrode is employed as a cathode material to fabricate an asymmetric supercapacitor (ASC) device with reduced graphene oxide (rGO) as an anode material, excellent energy storage performance (57.

A binder-free wet chemical synthesis approach to decorate nanoflowers of bismuth oxide on Ni-foam for fabricating laboratory scale potential pencil-type asymmetric supercapacitor device.

The present study involves the synthesis of a bismuth oxide (BiO) electrode consisting of an arranged nano-platelets for evolving a flower-type surface appearance on nickel-foam (BiO-Ni-F) by a simple, inexpensive, binder-free and one-step chemical bath deposition (CBD) method, popularly known as a wet chemical method. The as-prepared BiO on Ni-foam, as an electrode material, demonstrates 557 F g specific capacitance (SC, at 1 mA cm), of which 85% is retained even after 2000 cycles. With specific power density of 500 kW kg, the BiO-Ni-F electrode documents a specific energy density of 80 Wh kg.

Enhancing the Directed Self-assembly Kinetics of Block Copolymers Using Binary Solvent Mixtures.

The rapid pattern formation of well-ordered block copolymer (BCP) nanostructures is practical for next-generation nanolithography applications. However, there remain critical hurdles to achieve the rapid self-assembly of BCPs with a high Flory-Huggins interaction parameter (χ), owing to their slow kinetics. In this article, we report that a binary solvent vapor annealing methodology can significantly accelerate the self-assembly kinetics of poly(dimethylsiloxane-b-styrene) (PDMS-b-PS) BCPs with a high-χ.

Anti-counterfeit nanoscale fingerprints based on randomly distributed nanowires.

Counterfeiting is conducted in almost every industry, and the losses caused by it are growing as today's world trade continues to increase. In an attempt to provide an efficient method to fight such counterfeiting, we herein demonstrate anti-counterfeit nanoscale fingerprints generated by randomly distributed nanowires. Specifically, we prepare silver nanowires coated with fluorescent dyes and cast them onto the surface of transparent PET film.

Two-minute assembly of pristine large-area graphene based films.

We report a remarkably rapid method for assembling pristine graphene platelets into a large area transparent film at a liquid surface. Some 2-3 layer pristine graphene platelets temporally solvated with N-methyl-2-pyrrolidone (NMP) are assembled at the surface of a dilute aqueous suspension using an evaporation-driven Rayleigh-Taylor instability and then are driven together by Marangoni forces. The platelets are fixed through physical binding of their edges.

Complementary p- and n-type polymer doping for ambient stable graphene inverter.

Graphene offers great promise to complement the inherent limitations of silicon electronics. To date, considerable research efforts have been devoted to complementary p- and n-type doping of graphene as a fundamental requirement for graphene-based electronics. Unfortunately, previous efforts suffer from undesired defect formation, poor controllability of doping level, and subtle environmental sensitivity.

Device-oriented graphene nanopatterning by mussel-inspired directed block copolymer self-assembly.

Directed self-assembly of a block copolymer is successfully employed to fabricate device-oriented graphene nanostructures from CVD grown graphene. We implemented mussel-inspired polydopamine adhesive in conjunction with the graphoepitaxy principle to tailor graphene nanoribbon arrays and a graphene nanomesh located between metal electrodes. Polydopamine adhesive was utilized for facile and damage-free surface treatment to complement the low surface energy of pristine graphene.