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Penentuan Resistivitas Tak-Terkompensasi Cairan Ion Berbasis Imidazol dengan Metode EIS: Pengaruh Panjang Alkil dan Perbedaan Anion Patah, Aep; Rachmawati, Yulia; Utari, Riyadini; Rochliadi, Achmad
Jurnal Riset Kimia Vol 11, No 2 (2020): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i2.359

Ionic liquids have interesting properties because they have several advantages compared to conventional organic solvents, such as high thermal stability, high viscosity, good solvent properties, non-flammable, and non-volatile. In electrochemistry, ionic liquids can be used as solvents without the addition of electrolytes. However, ionic liquids still have resistivity properties (uncompensated resistance), thus ohmic drop measurements are needed for a potential correction. Imidazole-based ionic liquids, which are known for their high conductivity and commonly used as a solvent, have been measured of their resistivity as a function of temperature, and type of their cations/anions. Electrochemical Impedance Spectroscopy (EIS) method was chosen to measure the resistivity of ionic liquids and Bode plot was generated for the analysis of the results. The measured resistivities of ionic liquids are in the range of 420 to 1500 ohm. It is concluded that the resistivity of the imidazole-based ionic liquid is influenced by the size of their constituent ions, the viscosity, and the resistance is decreased with increasing temperature.

EFFECT OF CRYSTALLINITY TO OVERPOTENTIAL ON Ni₃Fe ALLOY AS ELECTROCATALYST IN HYDROGEN EVOLUTION REACTION Qonita Mu'minah; Achmad Rochliadi; Aep Patah
Jurnal Sains Materi Indonesia Vol 21, No 3: APRIL 2020
Publisher : Center for Science & Technology of Advanced Materials - National Nuclear Energy Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17146/jsmi.2020.21.3.5963

EFFECT OF CRYSTALLINITY TO OVERPOTENTIAL ON Ni3Fe ALLOY AS ELECTROCATALYST IN HYDROGEN EVOLUTION REACTION. Ni-Fe alloys can be used as electrocatalyst for the hydrogen evolution reaction (HER) in an alkaline solution. HER consumed highly energy and overpotential driven. The overpotential value corresponding to the electron transfer in reaction can be affected either by metal combination or alloy as a cathode. Ni₃Fe alloy had been successfully synthesized by the electrodeposition method using direct-current (DC) on a 304 L type stainless steel substrate. The modified Watts bath deposition was used NiCl2·6H2O and FeCl3·6H2O as precursors of the alloy. The optimum conditions of the reaction were obtained at pH of the solution is 2.20±0.02 with 25 mA/cm² current density at 55 °C for 160 minutes. Ni₃Fe alloy was characterized by Powder X-ray Diffraction (PXRD), Energy-Dispersive X-ray Spectroscopy (EDX), and Scanning Electron Microscopy (SEM). The electrocatalytic property of Ni3Fe alloy was electrochemically measured in 1 M KOH solution by polarization method using a Tafel plot with a scanning rate of 1 mV/s. As a result, the mass ratio of Ni²+ /Fe³+ in bath deposition influenced the electrocatalytic property of Ni₃Fe alloy. Ni₃Fe alloy with a higher crystallinity lowered the overpotential value of HER up to 67% compared to Ni metal.

Penentuan Resistivitas Tak-Terkompensasi Cairan Ion Berbasis Imidazol dengan Metode EIS: Pengaruh Panjang Alkil dan Perbedaan Anion Aep Patah; Yulia Rachmawati; Riyadini Utari; Achmad Rochliadi
Jurnal Riset Kimia Vol. 11 No. 2 (2020): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v11i2.359

Ionic liquids have interesting properties because they have several advantages compared to conventional organic solvents, such as high thermal stability, high viscosity, good solvent properties, non-flammable, and non-volatile. In electrochemistry, ionic liquids can be used as solvents without the addition of electrolytes. However, ionic liquids still have resistivity properties (uncompensated resistance), thus ohmic drop measurements are needed for a potential correction. Imidazole-based ionic liquids, which are known for their high conductivity and commonly used as a solvent, have been measured of their resistivity as a function of temperature, and type of their cations/anions. Electrochemical Impedance Spectroscopy (EIS) method was chosen to measure the resistivity of ionic liquids and Bode plot was generated for the analysis of the results. The measured resistivities of ionic liquids are in the range of 420 to 1500 ohm. It is concluded that the resistivity of the imidazole-based ionic liquid is influenced by the size of their constituent ions, the viscosity, and the resistance is decreased with increasing temperature.

Pengaruh Perbandingan Massa Silikon/Silika terhadap Karbon pada Kinerja Anode Baterai Litium Ion dari Sekam Padi Achmad Rochliadi; Mohammad Alief Ramdhan; Aep Patah
Jurnal Riset Kimia Vol. 14 No. 2 (2023): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v14i2.624

This study aims to investigate the possible utilization of silica (SiO2) and silicon (Si) derived from rice husks as anode materials in lithium-ion batteries (LIBs). SiO2 and Si have impressive theoretical capacities of 1965 and 4200 mAh/g, respectively. However, their direct use as LIBs anodes faces challenges such as substantial volume changes during battery charging and discharging, as well as low electrical conductivity. Consequently, a common approach is to create nanostructures of SiO2 and Si, such as nanoparticles, nanowires, and nanotubes, and combine them with conductive matrices like carbon-based materials. In this study, the Si/SiO2/C composite was synthesized from rice husks, taking into account the mass ratio of Si/SiO2 to C. The process involved first separating SiO2 and C from rice husks and then synthesizing the composite using the ball mill method and activated molten salt aluminothermic reduction (AlCl3/NaCl). X-ray Diffraction (XRD) analysis confirmed the successful synthesis of the composite, as indicated by characteristic peaks of the constituent compounds. Scanning Electron Microscope (SEM) imaging showed non-uniform morphology with varying particle sizes. Tests results demonstrated that the Si/SiO2/C composite with a 3:1 ratio exhibited the most promising performance as a LIB anode, maintaining a high capacity of 280.48 mAh/g with a Coulombic Efficiency (CE) of 99% after 50 testing cycles. These findings suggest that silica and silicon compounds derived from rice husks hold great potential as efficient and durable anode materials for LIBs applications.

Corrosion Inhibition Behavior of DL-Methionine and L-Tryptophan on Carbon Steel Achmad Rochliadi; Aep Patah; Claudia Claudia; Dadang Ramadhan
Jurnal Kimia Sains dan Aplikasi Vol 26, No 7 (2023): Volume 26 Issue 7 Year 2023
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.26.7.249-260

The cost-effective, efficient, and environmentally friendly corrosion inhibitors have become increasingly significant within the oil and gas sector. Consequently, this research was conducted to evaluate the corrosion inhibition behavior of the amino acids DL-Met and L-Tryp on carbon steel in acidic (0.05 M HCl), alkaline (0.05 M NH4OH), and neutral (3% NaCl) environments. This study used Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PDP) to assess the performance of amino acids as corrosion inhibitors. The EIS and PDP measurements revealed that DL-Met and L-Tryp exhibited corrosion inhibition effects exclusively in acidic conditions. In this environment, DL-Met demonstrated a corrosion inhibition efficiency (η) of 49.7% at a concentration of 525 ppm, while L-Tryp reached an efficiency of 87.08% at a concentration of 25 ppm. Under the same conditions, DL-Met reduced the corrosion rate from 10 mm/year to 4.468 mm/year, and L-Tryp reduced it from 10.95 mm/year to 5.003 mm/year. However, the corrosion inhibition activity of DL-Met and L-Tryp in neutral and alkaline conditions did not yield positive results according to EIS measurements. In neutral conditions, 100 ppm DL-Met exhibited -22.46% inhibitory activity. Meanwhile, in alkaline conditions, 150 ppm DL-Met and 5 ppm L-Tryp exhibited inhibition efficiencies of -72.39% and -81.9%, respectively. This research aims to provide the oil and gas industry with a natural-based corrosion inhibitor alternative, offering a solution to corrosion-related challenges in acidic conditions.

Pengaruh Variasi Dopan Asam Terhadap Kinerja Baterai Sekunder Polianilina|Zn Akbar, Said Ali; Suendo, Veinardi; Rochliadi, Achmad
CHEESA: Chemical Engineering Research Articles Vol. 3 No. 1 (2020)
Publisher : Universitas PGRI Madiun

Studi tentang baterai sekunder polianilina(PAni)|Zn telah banyak dikembangkan, tetapi sejauh ini masih belum ada penjelasan mengenai pengaruh asam terhadap kinerja baterai tersebut. PAni disitensis menggunakan metoda elektrodeposisi dengan tegangan 0,7 V selama 30 menit. PAni hasil sintesis dikarakterisasi menggunakan Voltammetri dan Spektroskopi Inframerah. Baterai PAni|Zn didesain dalam bentuk sandwich, kemudian pengukuran kinerja digunakan impedansi serta pengisian-pengosongan. Baterai dengan elektroda PAni-Cl dan PAni-Br mempunyai kinerja yang lebih baik dengan specific capacity saat ke-60 yaitu 55,4 dan 37,4 mAh g-1. Pengukuran impedansi pada baterai dengan elektroda PAni-Cl, PAni-Br, dan PAni HClO4, menunjukan resistance solution (Rs) secara berurutan yaitu 1,38; 2,56; dan 3,03 W dan resistance charge transfer (Rct) 2,24; 2,97; dan 7,71 W. Oleh sebab itu, baterai PAni|Zn dengan dopan HCl menunjukkan kinerja terbaik dibanding dengan asam yang lain.

Conductivity and mechanical properties of PEO/PVA/UiO-66 composite polymers for membrane of lithium-ion batteries Patah, Aep; Rochliadi, Achmad; Husein, Aditya; Ramadhan, Dadang
Communications in Science and Technology Vol 9 No 2 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.2.2024.1515

Lithium batteries are crucial for energy storage in electronics, transportation, and industrial sectors. However, lithium-ion battery separators such as Celgard require significant improvements, particularly in ionic conductivity (?). Combining Metal-Organic Frameworks (MOFs) with polymers is expected to create a separator membrane that enhances conductivity and mechanical properties in lithium-ion batteries. UiO-66 MOFs were synthesized using the solvothermal method at 120? and then composited with polyethylene oxide (PEO) and polyvinyl alcohol (PVA) polymer membranes using the solution casting method. The UiO-66 MOFs/PEO/PVA polymer composites were made by varying the UiO-66 content from 2% to 8% (w/w) while keeping a constant LiPF6 concentration of 9% (w/w). These composites were characterized using X-ray Diffraction (XRD) and Fourier-Transform Infrared spectroscopy (FTIR). Subsequently, the EIS test and tensile tests assessed the performance of the composite membranes. The resulting membrane with 6% (w/w) UiO-66 MOFs exhibited a conductivity (?) of 5.60 × 10–3 S cm–1 and a tensile strength of 32.5 MPa.

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