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All Journal JURNAL KIMIA SAINS DAN APLIKASI Jurnal Teknik : Majalah Ilmiah Fakultas Teknik Unpak
Irawan, Robin
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Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Electrical & Electronics Engineering Engineering Environmental Science Transportation

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Synthesis and Characterization of rGO Using a Combination Hummers Method and Hydrothermal Reduction Pardede, Maichel Letare; Jonathan, Nicholas; Irawan, Robin; Nugroho, Agung; Susanti, Ratna Frida
Jurnal Kimia Sains dan Aplikasi Vol 28, No 7 (2025): Volume 28 Issue 7 Year 2025
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.28.7.396-404

Abstract

Reduced graphene oxide (rGO) was successfully synthesized through a combination of two oxidation methods. The Hummers method was employed to synthesize graphite oxide (GrO), followed by a hydrothermal reduction technique to obtain a more ordered rGO structure. X-ray diffraction (XRD) analysis confirmed the transformation of GrO to rGO, as indicated by an interlayer spacing of 0.35–0.40 nm. This value reflects the crystalline characteristics and multilayer nature of the structure. The calculated crystallite size yielded La = 5.825 nm and Lc = 0.967 nm, suggesting a relatively high degree of crystallinity. Raman spectroscopy revealed an increase in structural disorder after the reduction process, as shown by an ID1/IG ratio of 1.771, which indicates the formation of structural defects due to the removal of oxygen-containing groups. Meanwhile, the IG/ID3 ratio of 1.039 confirms that the carbon atoms in rGO are arranged in a hexagonal graphite lattice. Additionally, the I2D/IG ratio of 0.321 indicates the presence of a multilayer structure. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX) showed that the rGO consists of graphene layers exhibiting folding and wrinkling, likely caused by thermal fluctuations during reduction at 180°C. The success of the reduction process was further supported by the increase in the C/O ratio from 2.42 in GrO to 5.39 in rGO. Electrochemical characterization by cyclic voltammetry (CV) demonstrated that rGO exhibits pseudocapacitive behavior, achieving a specific capacitance of 408.661 F/g at a scan rate of 5 mV/s. Overall, the combined synthesis approach employed in this study successfully produced rGO with favorable morphology and promising electrochemical properties, highlighting its potential for energy storage applications such as supercapacitors.
POLA PENYEBARAN DAN PENILAIAN SUMBER DAYA BATUBARA DAERAH GERAMAT DAN SEKITARNYA Adhitia, Iit; Solihin, Solihin; Pamungkas, Helmi Setia Ritma; Irawan, Robin
Jurnal Teknik | Majalah Ilmiah Fakultas Teknik UNPAK Vol 25, No 1 (2024): Jurnal Teknik : Majalah Ilmiah Fakultas Teknik UNPAK
Publisher : Universitas Pakuan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33751/teknik.v25i1.10215

Abstract

ABSTRAK Daerah penyelidikan berada di area Geramat dan sekitarnya, Kecamatan Merapi Selatan, Kabupaten Lahat, Provinsi Sumatera Selatan termasuk bagian dari Cekungan Sumatera Selatan yang diestimasikan mengandung batubara cukup besar dikarenakan cekungan ini disusun oleh litologi yang terendapkan pada lingkungan darat – transisi sebagai bagian Formasi Muara Enim, terdapat formasi lainnya yang berdekatan yaitu Formasi Gumai, Formasi Air Benakat, Formasi Kasai, Andesit, serta Satuan Gunung Api Muda. Pola penyebaran batubara daerah penelitian berarah umum tenggara – barat laut, hal ini di karenakan pola penyebaran batubara didaerah penelitian masih berhubungan dengan hasil proses geologi regional yaitu adanya pola lipatan antiklin dan sinklin serta sesar mendatar sebagai pengendali utama pola penyebaran seam batubara di area penyelidikan, sedangkan estimasi sumberdaya batubara daerah penelitian yaitu 8.900.975,6 ton untuk  sumberdaya tereka, 2.815.829,8 ton untuk sumberdaya tertunjuk, dan 854.850,8 ton untuk sumberdaya terukur, dengan total sumberdaya 12,571,656.1 ton. Batubara di daerah penelitian dijumpai pada bagian selatan  daerah penelitian, dan untuk menentukan prospek atau tidaknya batubara didaerah penelitian harus dilakukan penelitian lebih lanjut, untuk mengetahui ketebalan dan penyebaran berdasarkan data bor, striping rasio, dan analisis kualitas batubara. Kata Kunci : cekungan sumatera selatan, estimasi sumber daya, pola penyebaran  ABSTRACT The investigation area is in the Geramat area and its surroundings, South Merapi District, Lahat Regency, South Sumatra Province, including part of the South Sumatra Basin, which is estimated to contain quite a lot of coal because this basin is composed of lithology deposited in a terrestrial environment - transitional as part of the Muara Enim Formation. Other formations nearby, namely the Gumai Formation, Air Benakat Formation, Kasai Formation, Andesite, and the Young Volcano Unit. The coal distribution pattern in the research area has a general direction of southeast - northwest. This is because the coal distribution pattern in the research area is still related to the results of regional geological processes, namely the presence of anticline and syncline fold patterns and horizontal faults as the main controller of the coal seam distribution pattern in the investigation area. The projected coal resources for the research area are 8,900,975.6 tonnes inferred, 2,815,829.8 tonnes indicated, and 854,850.8 tonnes measured, for a total resource of 12,571,656.1 tonnes. Coal is found in the southern part of the research area, and more research is needed to determine thickness and distribution based on drill data, striping ratio, and coal quality analysis. Keywords: south sumatra basin, resource estimation, distribution patterns
Co-Authors Adhitia, Iit Helmi Setia Ritma Pamungkas Jonathan, Nicholas Nugroho, Agung Pardede, Maichel Letare Ratna Frida Susanti Solihin Solihin