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Journal : International Journal of Sustainable Transportation Technology

The Effects of Grain Size, Oxidizers and Catalysts on Band Gap Energy of Gelam-Wood Carbon Syarif, Nirwan; Rohendi, Dedi; Haryati, Sri; Dewi, Claudia
http://dx.doi.org/10.31427/IJSTT.2019.2.2.5
Publisher : Unijourn Publisher

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Abstract

The research of the effects of grain size, oxidizers, and catalysts on band gap energy of gelam-wood carbon has been conducted in which the carbons were produced from gelam-wood pyrolysis in high temperatures. The instrumentations used in this study were UV-Vis, FTIR spectrophotometer, and SEM. SEM and FTIR were used to characterize the morphology and the functionality of the carbon surface. UV-Vis spectrograms showed that the electronic property of carbon such as band gap was affected when grain size and surface area were changed. The increase of the functional groups in carbon occurred as the surface area of the carbon was increased. Band gap energy of crystalline carbon became much lower along with the increase in grain size due to the effects of bands-broadening. FTIR spectrograms showed that the carbon contained of hydroxyl and carboxylic groups. The hydroxyls were derived from steam-oxidized carbon that was provided narrower in the interlayer distance and lower-set band gap energy. Carboxylic groups were derived from acid nitric oxidation causing flat layer to become curved. The layers were wider and the band energy was higher. The main factor that affects the electronic structure of metal oxide in carbon/metal oxide composites was atomic alignments. The band gap energy increased along with the increase of the asymmetry alignments in metal oxide.
Electrochemical Evaluation of Lithium-Ion Battery with Anode of Layer-Reduced Biocarbon and Cathode of LiFePO4 Syarif, Nirwan; Rohendi, Dedi; Sya'baniah, Nyimas
http://dx.doi.org/10.31427/IJSTT.2019.2.2.4
Publisher : Unijourn Publisher

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Abstract

The application of reduced carbon anode layer and LiFePO4 cathode was conducted in laboratory-scale battery. Both electrodes were fabricated into lithium - ion battery with LiCl electrolyte in both gel and liquid based. The carbon was prepared by using Hummer method and solvent sonification to exfoliate the carbon layer from biocarbon. The battery performance tests were carried out in potentiostat for Cyclic Voltammetry (CV) and galvanostatic measurements. The highest current of CV measurement can be obtained in the battery with reduced carbon layer anode and 20% of liquid electrolyte. It was calculated that the same battery produced the highest energy and power. Current - Voltage profile is relatively stable in CV of batteries with 40% electrolytes in both gel and liquid media. All batteries have two peaks in both anodic and cathodic. The reduction peaks show in around 0.5 and 1.5 volts. The cathodics show in around –0.5 and –1.5 volts. The best power and energy values are given by battery with rCNSO anode and 20% liquid electrolyte. Galvanostatic profiles show that the 40% electrolytes in the batteries produces a slower discharging process. It was revealed that applying anode of layer reduced biocarbon as the battery electrode caused the discharging to run faster. The highest slope value of the galvanostatic curve can be found in the battery with the electrode of oxidized starting material and 40% of gel electrolyte, while the lowest can be found in 20% gel electrolyte with the same electrode.
Module Stabilizing of Biocarbon Based Electrochemical Capacitor Syarif, Nirwan; Rohendi, Dedi; Sudarsono, Wulandari; Wong, Wai
http://dx.doi.org/10.31427/IJSTT.2019.2.1.5
Publisher : Unijourn Publisher

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Abstract

One of the disadvantages of the electrochemical capacitor (EC) or supercapacitor compared with batteries is its low specific energy. It limits of EC to meet the energy needs of the electrical-electronic devices, such as electric cars. To overcome those limitations, it needs a serial circuit to increase the voltage range, and parallel circuits to increase the storage capacity. Practically, the module that built from 2-6 pieces of 2.5V EC cells will not feasible to make the module with the voltage of 5-15 V. It was found that the voltage of the EC cell could decreases to about 2.0 V, so that the capacitance of the module significantly reduced. This paper reports the basic methods that can be applied to overcome these problems by using a stabilizing or balancing component. The balancing components used in this study were a resistor, a Zener diode, and a Schottky diode. Each component was attached to every EC cell. The influence of the Zener and Schottky diode was observed as a component of a blocking diode. The results showed that the use of a 100-ohm resistor and Zener diode reduces voltage peaks while the use of blocking diode modules leads to increased discharge time. In general, there was no significant change in the charging time, both with and without the balancing and blocking component.
A Review on Production of Hydrogen from Renewable Sources and Applications for Fuel Cell Vehicles Rohendi, Dedi; Rahmah, Dea; Yulianti, Dwi; Amelia, Icha; Sya'baniah, Nyimas; Syarif, Nirwan; Rachmat, Addy
http://dx.doi.org/10.31427/IJSTT.2018.1.2.5
Publisher : Unijourn Publisher

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Abstract

Hydrogen gas is an energy carrier that has many advantages, including energy density for high mass and environmentally friendly. Hydrogen can be produced from various sources by numerous methods. Hydrogen production from renewable sources is interesting, due to the sustainable and inexpensive supply of the raw materials. Among the sources of renewable raw materials for hydrogen production are water and biomass with various production methods. It consists of the electrolysis of water with acidic and basic conditions, as well as thermochemical and biochemical biomass conversion.
Co-Authors ACHEAMPONG, KENNEDY Addy Rachmat Ade Gafar Abdullah, Ade Gafar Ade Gaffar Abdullah, Ade Gaffar Adelia, Ory Adhiyanti, Nurmalina Agus Setiawan Aldes Lesbani Amelia, Icha Amelia, Icha Ana Arrumaisha, Nissa Asep Yudi Permana Assaidah, Assaidah Barlin Barlin Bijak Riyandi Ahadito Budhi Setiawan Budi Mulyanti Budiman, Rahmadi Dedy Suryadi Dewi, Claudia Edy Herianto Majlan, Edy Herianto Eka Daryanto, Eka Fakhili Gulo Fatma Fatma Fatmawati Fatmawati Fauzan, Mochamad Patra Bani Fauzan, Mochamad Rizal Felicity, Felicity Firanda, Dera Okta Gigin Gantini Putri Hanapi, Zaliza Hanissa Okitasari Hanissa Okitasari Hary Widjajanti Heri Sutarno Hikmawan, Rizki Indriana Sari Soleha Iskandar, Naufal Nadhif Rabbani Iwa Kuntadi Jefri Jefri Kamin Sumardi Kamin Sumardi Koehler, Thomas Larutama, Wiku Menik Setyowati Mokhamad Syaom Barliana Muhammad Adli Rizqulloh Muhammad Dzulfikar A Muhammad Faizal MUHAMMAD SAID Muhammad Said Muktiarni Mustika Nuramalia Handayani Nirwan Syarif Nirwan Syarif, Nirwan Normah Normah, Normah Nugraha, Agri Triya Nurcholifah, Yollanda Oduro-Okyireh, George Oduro-Okyireh, Theodore Permana, Muhammad Aditya Poedji Loekitowati Hariani Pramudita, Resa Purnawan Purnawan Rahmah, Dea Ramadhan, Muhammad Oka Rasim, R Ria Komala Risfidian Mohadi Roer Eka Pawinanto, Roer Eka Salni Saripudin Saripudin Septiadi, Jaka Shandyka, Muhammad Fajar Siregar, Batu Mahadi Sri Haryati Steven Julianto Situmeang Suamrdi, Kamin Subarna, Bambang Sudarsono, Wulandari Sya'baniah, Nyimas Sya'baniah, Nyimas Syabaniah, Nyimas Febrika Syahputra, Rio Aldo Syarif, Nirwan Syarif, Nirwan Syarif, Nirwan Syarif, Nirwan Sya’baniah, Nyimas Febrika Tarmizi Taher Tri Kurnia Dewi Utama, Muhammad Prima Wong, Wai Yulianti, Dwi Yulianti, Dwi Hawa Yulinar Adnan Zainal Fanani