Impact of Thermally Reducing Temperature on Graphene Oxide Thin Films and Microsupercapacitor Performance.

In this work, a thermally reduced graphene oxide (TRGO) thin film on microscopic glass was prepared using spray coating and atmospheric pressure chemical vapour deposition. The structure of TRGO was analysed using X-ray diffraction (XRD) spectroscopy, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, and ultraviolet-visible spectroscopy (UV-Vis) suggesting a decrease in oxygen functional groups (OFGs), leading to the restacking, change in colour, and transparency of the graphene sheets. Raman spectrum deconvolution detailed the film's parameters, such as the crystallite size, degree of defect, degree of amorphousness, and type of defect.

Novel Thermally Reduced Graphene Oxide Microsupercapacitor Fabricated via Mask-Free AxiDraw Direct Writing.

We demonstrate a simple method to fabricate all solid state, thermally reduced graphene oxide (TRGO) microsupercapacitors (µ-SCs) prepared using the atmospheric pressure chemical vapor deposition (APCVD) and a mask-free axiDraw sketching apparatus. The Fourier transform infrared spectroscopy (FTIR) shows the extermination of oxygen functional groups as the reducing temperature (RT) increases, while the Raman shows the presence of the defect and graphitic peaks. The electrochemical performance of the µ-SCs showed cyclic voltammetry (CV) potential window of 0-0.

Enhanced Electrochemical Behavior of Peanut-Shell Activated Carbon/Molybdenum Oxide/Molybdenum Carbide Ternary Composites.

Biomass-waste activated carbon/molybdenum oxide/molybdenum carbide ternary composites are prepared using a facile in-situ pyrolysis process in argon ambient with varying mass ratios of ammonium molybdate tetrahydrate to porous peanut shell activated carbon (PAC). The formation of MoO and MoC nanostructures embedded in the porous carbon framework is confirmed by extensive structural characterization and elemental mapping analysis. The best composite when used as electrodes in a symmetric supercapacitor (PAC/MoO/MoC-1//PAC/MoO/MoC-1) exhibited a good cell capacitance of 115 F g with an associated high specific energy of 51.

Ex-situ nitrogen-doped porous carbons as electrode materials for high performance supercapacitor.

Nitrogen (N) doping of porous carbon materials is an effective strategy for enhancing the electrochemical performance of electrode materials. Herein, we report on ex-situ (post) nitrogen-doped porous carbons prepared using a biomass waste, peanut shell (PS) as a carbon source and melamine as the nitrogen source. The synthesis method involved a two-step mechanism, initial chemical activation of the PS using KOH and post N-doping of the activated carbon.

Nitridation Temperature Effect on Carbon Vanadium Oxynitrides for a Symmetric Supercapacitor.

In this work, porous carbon-vanadium oxynitride (C-VNO) nanostructures were obtained at different nitridation temperature of 700, 800 and 900 °C using a thermal decomposition process. The X-ray diffraction (XRD) pattern of all the nanomaterials showed a C-VNO single-phase cubic structure. The C-VNO obtained at 700 °C had a low surface area (91.

Electrochemical analysis of Na-Ni bimetallic phosphate electrodes for supercapacitor applications.

Bimetallic sodium-nickel phosphate/graphene foam composite (NaNi(PO)/GF) was successfully synthesized using a direct and simple precipitation method. The hierarchically structured composite material was observed to have demonstrated a synergistic effect between the conductive metallic cations and the graphene foam that made up the composite. The graphene served as a base-material for the growth of NaNi(PO) particles, resulting in highly conductive composite material as compared to the pristine material.

Three dimensional vanadium pentoxide/graphene foam composite as positive electrode for high performance asymmetric electrochemical supercapacitor.

The electrochemical performance of hydrothermal synthesized three dimensional (3D) orthorhombic vanadium pentoxide (VO) nanosheets and vanadium pentoxide/graphene foam (VO/GF) composites at different mass loading of GF were successfully studied. The optimized VO/GF-150 mg composite provided a high specific capacity of 73 mA h g, which was much higher than that the pristine VO (60 mA h g) nanosheets at a specific current of 1 A g. A hybrid capacitor was also fabricated by adopting a carbon-based negative electrode obtained from the pyrolysis of an iron-PANI polymer (C-Fe/PANI) mixture and the 3D VO/GF-150 mg composite as the positive electrode in 6 M KOH electrolyte.