Advanced Nano Research

Biocarbon Derived from Seeds of Palmyra Palm Tree for a Supercapacitor Application

K Vengadesan — 2023-04-06

Carbon-based materials are among the most promising materials for future electrochemical energy storage and conversion. Eco-friendly Palmyra palm seed derived microporous biocarbon was fabricated on the graphitic sheet. Palm seed derived carbon was carbonized by using 0.5 M H₂S0₄ without any activating agent. Morphological characterization of PSDC investigated through SEM (Scanning Electron Microscopy). It shows PSDC is microporous with carbon network like structure. Physiochemical characterization performed through XRD, FT-IR and Raman studies. Raman studies confirm the PSDC having carbon based material. Electrochemical performance by using Cyclic voltammetry (CV), Galvanostatic charge discharge (GCD) and Electrochemical Impedance spectroscopy (EIS). PSDC exhibits the specific capacitance of 220 F/g at 5 A and 276.5 F/g at 1 A current as well as remarkable capacitance retention after 500 cycles is 63.1%. It shows PSDC having remarkable electrochemical storage application.

Temperature Dependence on Structural Properties of Liquid Phase Synthesized ZnO

Nii Abekah Akwetey Armah — 2023-04-06

Transparent conducting oxide material, ZnO nanoparticles has been synthesized using inexpensive and eco-friendly synthesis procedures with less or environmental pollutants and no liquid waste products. The effect of the temperatures on the structural properties for the synthesized ZnO nanocrystals has been investigated. In this study, we report an easy, low-cost, re-producible method for synthesizing ZnO nanoparticles by means of the liquid phase method. The ZnO nanocrystals were synthesized using the wet chemical route and the effect of temperature variation on the structural properties of investigated synthesized using powder x-ray diffractogram (XRD). The temperatures for the synthesis were varied from 120 °C to 200 °C in steps of 20 °C. The results show that, during the first stage of the synthesis of ZnO (at 120 °C), the XRD diffraction pattern confirms the cubic structure of zinc peroxide and the XRD pattern of the samples obtained at temperatures of 140 °C, 160 °C, 180 °C and 200 °C were confirmed to be hexagonal (wurtzite) crystal structure of ZnO. The XRD diffraction patterns of the 140 °C and 160 °C samples show some impurity phases which were associated with the zinc acetate by-product which is a colloid complex of water and methyl succinate and were removed by evaporation as temperatures were increased to 180 °C and 200 °C respectively. As temperature increases, the peak of the diffractograms of the sample becomes sharper and narrow indicating a decrease in width. A shift in peak positions to higher angles was observed and the positional parameter, bond angle, β, average crystallite size, APF, number of unit cells and density generally increase with temperature. However, the lattice parameters ‘a’ and ‘c’, bond lengths b and b₁, bond angle, α, dislocation density, strain and unit cell volume were found to generally decrease with temperature.

Fabrication Method of Carbon-based Materials in CH4/N2 Plasma by RF-PECVD and Annealing Treatment for Laser Diodes

Arwa Saud Abbas — 2023-09-18

The present research addresses the synthesis of carbon materials thin films by RF-PECVD in N₂/CH₄ gas mixture. Carbon materials film was formed at 40/48 sccm of CH₄/N₂ of the total gas flow rate ratio CH₄/CH₄+N₂ = 0.45 and 200/100 W HF/LF power at a deposition temperature of 350 ^oC and 1000 mTorr pressure. Then, post-annealing of carbon materials film took place at 400 ^oC by means of RTA under N₂ flow. The formation of carbon nanostructures was investigated by scanning electron microscopy, energy dispersive X-ray, Raman spectroscopy, and atomic force microscopy, respectively. AFM shows that the films consisted of nanocrystalline grains. The surface morphology and structural characteristics of materials were studied as a gas flow function and substrate temperature. EDX results indicated the carbon presence, and Raman spectroscopy analysis revealed two broad bands: D-band 1381.64 cm⁻¹ and G-band 1589.42 cm⁻¹. The temperature-dependent post-annealing of carbon materials plays a key role in the graphite crystallites growth at high substrate temperatures. Our results indicate carbon materials incorporation for laser diode applications.