The β-Ni(OH)2 nanoparticles and their nanohybrid with 5% CNTs have been synthesized by facile hydrothermal and ultra-sonication method. The structural and phases analysis of the prepared sample was investigated by XRD and FT-IR analysis. The effect of CNTs on the electrical and electrochemical properties of the nanohybrid was determined via current-voltage (I-V) and electrochemical measurements. The observed higher electrical conductivity (1.37 × 10−2 Sm−1) of the β-Ni(OH)2@CNTs nanohybrid than the Ni(OH)2 nanoparticles (1.2 × 10−8 Sm−1) was due to the effective interaction between the CNTs and Ni(OH)2 nanoparticles. Moreover, the higher gravimetric capacitance (724 Fg−1) and lower charge transfer resistance (Rct) of the nanohybrid was also observed. This was due to the synergistic effects between the electrolytic double-layer capacitance (EDLC) of the CNTs and pseudocapacitance (PSCs) of the Ni(OH)2 nanoparticles (NPs). The evenly distributed CNTs not only act as a capacitive supplement but also support the faradic reaction in the Ni(OH)2 nanoparticles to enrich the gravimetric capacitance. The observed results express the potential of the β-Ni(OH)2@CNTs nanohybrid as a positive electrode for modern energy storage devices.

Nickel hydroxide nanoparticles and their hybrids with carbon nanotubes for electrochemical energy storage applications

Superoxide anion: Critical source of high performance antibacterial activity in Co-Doped ZnO QDs

• Ni/carbon nanostructure materials have been synthesized from biomass waste using simple approach. • Synthesis of carbon nanotubes or amorphous carbon nanostructures can be controlled by adjusting the temperature process. • NiO/ porous amorphous carbon nanostructure (PACNS) material delivered specific capacitance of 508 F g −1 at 1 A g −1 . • The NiO/PACNS electrode shows a capacitance retention rate of 78% at 5 A g −1 after 3000 cycles. Herein, nanostructured nickel metal, oxide, and oxyhydroxides have been successfully grown on various types of carbon nanostructures (CNS) via a simple, low cost and eco-friendly route derived from biomass waste materials. Nickel oxide and oxyhydroxide phases could be detected in the roasted precursor materials before pyrolysis as confirmed by X-ray diffraction (XRD) analysis. Transmission electron microscopy (TEM) images showed that these samples were composed mainly of porous amorphous carbon nanostructures. Whereas nickel-metal and nickel oxyhydroxide were the predominant detected phases after pyrolysis in addition to the graphite and carbon phases in the form of carbon nanotubes as confirmed by XRD analysis and TEM investigation, respectively. These composites were explored as potential electrodes for supercapacitor application delivering satisfactory specific capacitance values beside its remarkable charge/discharge reversibility. Among them, the formed porous amorphous carbon nanostructure sample decorated with NiO species displayed the highest capacitive performance. This sample delivered a specific capacitance of 508 F g −1 at 1 A g −1 . Moreover, the cycling stability behavior of this sample at 5 A g −1 delivered 78% of its initial capacity after 3000 GCD cycles. The obtained results suggested that the prepared materials are a promising candidate as electrode material for energy storage applications. 

High-performance electrode materials for supercapacitor applications using Ni-catalyzed carbon nanostructures derived from biomass waste materials

One-step for in-situ etching and reduction to construct oxygen vacancy modified MoO2/reduced graphene oxide nanotubes for high performance lithium-ion batteries

Designing an excellent acidic and alkaline general-purpose hydrogen evolution electrocatalyst plays an important role in promoting the development of the energy field. Here, a feasible strategy is reported to use the strongly coupled MoS2@sulfur and molybdenum co-doped g-C3N4 (MoS2@Mo-S-C3N4) heterostructure with transferable active centers for catalytic reactions in acidic and alkaline media. Research studies have shown that the unsaturated S site at the edge of MoS2 and the active N atom on the Mo-S-C3N4 substrate are, respectively, the active centers of acidic and alkaline hydrogen evolution reaction. Specifically, Mo-S-C3N4 is regarded as a synergistic catalyst for the active species MoS2 in acidic hydrogen evolution, while MoS2 acts as a co-catalyst when the alkaline active species are transferred to Mo-S-C3N4. The coordination of the electrons between the interfaces achieves a synergistic balance, which provides the optimal sites for the adsorption of the reactants. Such an electrocatalyst exhibits overpotentials of 193 and 290 mV at 10 mA cm-2 in 0.5 M H2SO4 and 1 M KOH, respectively, which was better than numerous previous reports. This research provides an outstanding avenue to realize multifunctional electrocatalysts.

Transferable Active Centers of Strongly Coupled MoS2@Sulfur and Molybdenum Co-doped g-C3N4 Heterostructure Electrocatalysts for Boosting Hydrogen Evolution Reaction in Both Acidic and Alkaline Media

Yuhan Wang

Papers

High-performance supercapacitor electrode based on 3D rose-like β-Ni(OH)2/rGO nanohybrid

High-performance Supercapacitor Electrode based on 3D Rose-like β-Ni(OH)2/rGO nanohybrid