Engineering triangular bimetallic metal-organic-frameworks derived hierarchical zinc-nickel-cobalt oxide nanosheet arrays@reduced graphene oxide-Ni foam as a binder-free electrode for ultra-high rate performance supercapacitors and methanol electro-oxidation.

From waste to value-added products: Evaluation of activated carbon generated from leather waste for supercapacitor applications

Facile one-step hydrothermal method for NiCo2S4/rGO nanocomposite synthesis for efficient hybrid supercapacitor electrodes

• 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

Herein, α-Ni(OH)2 ultrathin sheets on reduced graphene oxide layers were synthesized via a simple single-step precipitation process. The structure, morphology, and chemical composition of the as-synthesized α-Ni(OH)2/rGO hybrid structure are well characterized using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. A 30 wt% α-Ni(OH)2/rGO denoted as NG2 achieved a superb supercapacitor performance, displaying specific capacitance (capacity) of 1050 F g−1 (580 C g−1) at 1 A g−1 current density. The assembled supercapacitor delivered specific energy of 60 W h kg−1 at a specific power of 1.1 kW kg−1. Still, it retained a high specific power of 3.9 kW kg−1 at 43 W h kg−1, demonstrating a retention percentage of 88% after 4000 repetitive charge/discharge cycles.

Polyvinylpyrrolidone and freeze drying-assisted growth of an α-Ni(OH)2/reduced graphene oxide hybrid structure as a superior electrode material for supercapacitors

S.Y. Ahmed

Papers

High electrochemical energy-storage performance promoted by SnSe nanorods anchored on rGO nanosheets