Removal of Cu, Fe, and Zn from Peat Water by Using Activated Carbon Derived from Oil Palm Leaves

Heavy metal such as Cu, Fe, and Zn are the most serious contributers to environmental problems. The removal of heavy metal from the environment is the research interest nowdays. The adsorption of Cu, Fe and Zn from wastewater was investigated with various activated carbons as adsorbents. The activated carbons were produced from oil palm leaves by using multi-activation methods. The H3PO4, NaOH, ZnCl2 and KOH were chosen as chemical activating agents. Batch adsorption experiment was used to test the ability of activated carbon to remove Cu, Fe, and Zn from wastewater. The surface characteristics of activated carbon were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption isotherms. The Activated carbons were able to purify wastewater with a maximum turbidity level of 2.83 NTU. The AC-H3PO4 activated carbon showed the highest absorbability of Cu metal as 91.540%, while the highest absorbabilities of Zn and Fe metals were indicated by AC-KOH activated carbon of 22.853% and 82.244% absorption respectively. Therefore, these results enable the oil palm leaves to become a high potential for activated carbon as removal the heavy metals.</jats:p

Nickel Doping in ZnO Nanorod Synthesis: Effects of Nickel Concentration on Physical Properties of the Nanorod

Abstract ZnO nanorods have successfully been grown on the surface of FTO. The growth of ZnO nanorods was carried out using the seed-mediated growth method, whereas the Ni doping was carried at different concentrations. The effect of nickel doping on ZnO nanorods was observed using field emission scanning electron microscope (FESEM), UV-Vis spectroscopy, and X rays diffraction (XRD). ZnO nanorods having hexagonal shape were shown by FESEM images, and overlap of ZnOnanorods forming a nanoflowers with wider rod size. UV-Vis spectra showed that strong absorption occurred at a wavelength of 390-300 nm, the highest intensity of absorption was resulted by 15mM sample. The energy gap of the sample decreased as increasing its concentration. XRD pattern of the samples showed the diffraction peaks occurred at angles of 2θ = 31.72°, 34.45°, 36.20°, 47.50°, and 56.57° that represented the crystal plane orientation of (100), (002), (101), (102), and (110).</jats:p

The Effects of Different Activation Agents on the Physical and Electrochemical Properties of Carbon Electrodes Produced from Banana Stem Fiber

Abstract This study focuses on the effects of chemical activation materials on the physical and electrochemical properties of carbon electrodes made from banana stem fiber. The carbon electrodes were activated with different activators such as KOH, NaOH and ZnCl2 at a constant concentration of 0.5 M. Also, the electrodes were carbonized at a temperature of 550°C followed by a physical activation process using CO2 at 900°C for 2.5 hour, after which the density, surface morphology, element contents, degree of crystallinity and surface area of carbon electrodes were analyzed. In general, the activator used determines both the physical and electrochemical properties of the electrodes. Also, activating materials have the capacity to improve the physical properties of the samples as well as increase its specific capacitance. According to this research, AC-ZnCl2 shows better physical and electrochemical properties having a specific capacitance as high as 130 F g−1.</jats:p

Optical and Morphological Properties of ZnO Nanostructure by Coating Aluminium and Plasmonic Material

Abstract We provide a preliminary study of ZnO nanostructure synthesis by coating aluminium and metallic plasmonic Au-Ag using seed mediated hydrothermal method. The growth process is carried out on the FTO substrate and characterized using UV-Vis, XRD, FESEM and EDX spectrophotometer system. The UV-Vis spectrum shows that strong absorption occurs at wavelengths around 370 nm, for all samples. The XRD pattern shows three diffraction peaks at angles 2θ = 34.43°, 36.32° and 47.49°. Each peak corresponds to the crystal fields of (100), (002) and (101). Morphology of the samples shows the presence of ZnO nanorod. A compact and denser nanostructure also obtained.</jats:p

Preparation and Characterization Activated Carbon Based on Mesocarp of Bintaro Fruit as Electrode Materials Supercapacitor Cell Application

Abstract Supercapacitor is an energy storage device that has high energy and power density. One of the main component in supercapacitor cells is electrode. A production of activated carbon made from mesocarp of Bintaro fruit as a supercapacitor cell electrode has been successfully. Activated carbon electrodes were prepared through a pre-carbonization process, chemical with KOH 0.5 M activator, carbonization process using N2 gas and physical activation using CO2 gas. In this study, the physical activation process was carried out with temperature variations of 650°C, 750°C, 850°C and 950°C which of KAMBB-650, KAMBB-750, KAMBB-850 and KAMBB-950 respectively. Microstructure analysis shows amorphous structure for the carbon electrodes which is by the presence of peaks at an angel of 2θ around 24° and 44°. The increasing physical activation cause smaller Lchigh specific capacitance. In this study, the optimum temperature obtained in 850°C of KAMBB-850 sample. High specific capacitance as high as 267,6 F/g was found on KAMBB-850. The lowest capacitance obtained at carbonization temperature 950°C of KAMBB-650 sample with specific capacitance as high as 71,4 F/g.</jats:p

The Physical and Electrochemical Properties of Activated Carbon Electrode Derived from Pineapple Leaf Waste for Supercapacitor Applications

Abstract This study aims to the physical and electrochemical properties of the supercapacitor carbon electrodes derived from pineapple leaf waste. The production of carbon electrodes was conducted using combinations of chemical activation, carbonization, and physical activation. The chemical activation was carried out using a 0.9 M KOH activator. The carbonization and physical activation were conducted using a one-step process. The PAL-AC electrode was obtained showed porosity in the mesoporous range, large pore volume, and high specific surface area. The surface morphology of the PAL-AC electrode is dominated by carbon and nanofibers particles. The nanofibers diameter based on the SEM micrograph is in the range of 44-137 nm. Elemental contents of the PAL-AC electrode are dominated by carbon and oxygen with an atomic percentage of 86.03% and 9.49%, respectively. The XRD pattern of the PAL-AC electrode shows the presence of two wide peaks at scattering angle of 23° and 45°. The specific capacitance of the PAL-AC electrode as high as 127 F g−1 in 6 M KOH electrolyte solution using two-electrode configuration. The pineapple leaf waste based-carbon electrodes show promising potential for use as supercapacitor electrodes.</jats:p

Effect of Chemical Activation on the Physical Properties of Activated Carbon from Banana Empty Fruit Bunches as Heavy Metal Adsorbent

Abstract Heavy metal pollution was a headline issue for environmental degradation, both in water and soil environments. Reducing efforts of heavy metal can be carried out through the green system, such as activated carbon from agriculture waste. This paper investigates the properties of activated carbon from banana empty fruit bunches (BEFBs) for heavy metal adsorption. The activated carbon was produced using chemical activation under microwave-assisted. Potassium hydroxide (KOH) is used as an activating agent for concentrations of 2, 3, and 4 M, each sample denoted AC-2M, AC-3M, and AC-4, respectively. The microwave irradiation was performed by a commercial microwave oven with output power up to 630 W for 15 minutes. X-ray diffraction characterization result shows the lower stack length Lc occurs in a sample of AC-2M with a value of 10.966. The surface morphology of all samples shows the presence of non-uniformed pores. The EDX analysis reveals that carbon content of AC-2M is higher than other samples up to 78.86%, while the oxygen is lower (11.87%). FTIR spectrum shown that the activated carbon from BEFBs contain functional groups of C-H, C=C, C-C, C-OH, and CH2 at wavenumber 2887 cm−1, 2360.97 cm−1, 2339.5 cm−1, 1573 cm−1, 1393.63 cm−1, and 998.21 cm−1, respectively. As the best sample, AC-2M shows higher heavy metal adsorption as much as 87.41% for Pb and 62.35% for Cu.</jats:p

Porous Activated Carbon Binder-free Scleria sumatrensis Stem-Based for Supercapacitor Application

Abstract Green, sustainable and effective development technique to obtain high porous activated carbon biomass based is important to boosting supercapacitor performance with environmentally friendly effect as conversion system and energy storage devices. We reported porous activated carbon binder-free Scleria sumatrensis stem-based as electrode material high performance of symmetric supercapacitor. Precursor biomass of Scleria sumatrensis stem was converted into porous carbon through simple ZnCl2 impregnated with different concentration of 0.4M, 0.5M, 0.6M, and 0.7M at high-temperature phyrolysis. All samples confirmed good amorphous carbon with small amounts of oxidative compounds. In two-electrode system, the optimum sample of ACSS0.6 significantly boosting the specific capacitance as high as 142.62 F g−1 at scan rate of 1 mV s−1. Furthermore, the optimum energy density was found to be 19.80 Wh kg−1 at a maximum power density of 71.35 W kg−1 in 1 M H2SO4 aqueous electrolyte. These results confirm that the porous activated carbon binder-free Scleria sumatrensis stem-based through simple ZnCl2 impregnated as an electrode material to boosting the electrochemical behavior of supercapacitors.</jats:p

Fabrication of Carbon Electrodes from Sago Midrib Biomass with Chemical Variation for Supercapacitor Cell Application

Abstract Activated carbon with high porosity and controlled pores structure are widely applied as supercapacitor electrodes biomass derived from sago midrib (PS). Activated carbon based on sago midrib without chemical agent and using chemical agent ZnCl2 and NaOH by a concentration 0,5 M has been fabricated with a purpose to produce distribution of mesopores and micropores. Samples were carbonized at temperature 600°C using N2 gas followed by a physical activation process using CO2 gas at temperature of 700°C. The highest mass loss percentage of carbon electrode PS-ZnCl2 was 51,6% Microstructure analysis shows that amorphous structure for the activated carbon electrodes is shown by the presence of the peaks of 2θ around 240 and 440 with the highest Lc presented by ZnCl2. SEM characterization showed the domination of mesopores and a few of micropores presented by ZnCl2. EDX characterization showed the highest atomic carbon percentage is 90,27%. Specific capacitance was determined by cyclic voltammetry method and found the highest in PS-ZnCl2 was 138 F/g. The result from the physical and chemical properties, ZnCl2 is the best chemical agent from biomass-derived sago midrib for the best performance of supercapacitor cells.</jats:p

KOH Activation with Microwave Irradiation and its Effect on the Physical Properties of Orange Peel Activated Carbon

Abstract Chemical activation with assisted microwave irradiation was used to produced activated carbon from orange peel waste. The activating agent was potassium hydroxide (KOH) with concentrations of 2 M, 3 M, and 4 M. The microwave irradiation was done for 15 minutes with a 630 Watt output power. KOH concentration affected the physical properties of OP-ACxM. With increasing KOH concentration, the interlayer spacing (d002 and d100 ) grew, stack height (Lc ) increased, and stack width (La) dropped. The number of pores on the surface of OP-ACxM increased after the chemical activation process. In OP-ACxM, FTIR analysis reveals the presence of O-H, C-H, C-C, C=O, C=C, and C-O.</jats:p