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Synthesis of NiFe2O4/SiO2/NiO Magnetic and Application for the Photocatalytic Degradation of Methyl Orange Dye under UV Irradiation Poedji Loekitowati Hariani; Muhammad Said; Addy Rachmat; Salni Salni; Nabila Aprianti; Anisa Fitri Amatullah
Bulletin of Chemical Reaction Engineering & Catalysis 2022: BCREC Volume 17 Issue 4 Year 2022 (December 2022)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.17.4.15788.699-711

Abstract

NiFe2O4/SiO2/NiO magnetic was successfully synthesized using NiFe2O4, SiO2, and NiO as the core, interlayer, and shell, respectively. NiFe2O4/SiO2/NiO under UV light irradiation was used for photocatalytic degradation of methyl orange dye with different pH, catalyst dose, and initial dye concentration. This composite was characterized by X-ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR), Scanning Electron Microscopy-Electron Dispersive X-ray Spectroscopy (SEM-EDs), Vibrating Sample Magnetometer (VSM), UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS), and Point of Zero Charge (pHpzc). The results showed that the composite is a superparamagnetic material with a saturation magnetization value of 44.13 emu/g. It also has a band gap of 2.67 eV with a pHpzc of 6.33. The optimum conditions for photocatalytic degradation were at pH of 4; 0.50 g/L catalyst dose, and 10 mg/L initial concentration. NiFe2O4/SiO2/NiO degradation efficiency to methyl orange dye was 95.76%. The photocatalytic degradation in different concentrations follows the pseudo-first-order, where the greater the concentration, the smaller the constant rate (k). After five cycles of repeated usage, NiFe2O4/SiO2/NiO has good catalytic performance as well as efficient and favourable of a recyclable photocatalyst. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
The Influence of Catalyst Loading on Electrocatalytic Activity and Hydrogen Production in PEM Water Electrolysis Rohendi, Dedi; Amelia, Icha; Sya'baniah, Nyimas Febrika; Yulianti, Dwi Hawa; Syarif, Nirwan; Rachmat, Addy; Fatmawati; Majlan, Edy Herianto
Science and Technology Indonesia Vol. 9 No. 3 (2024): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2024.9.3.556-564

Abstract

The climate change caused by the widespread and continuous use of fossil fuels is a problem that needs to be addressed urgently. One of the solutions offered is through an energy transition towards the use of new or renewable and low-carbon fuels. Hydrogen gas as a carrier of energy is an alternative solution that has attracted the attention of researchers, due to its high combustion energy and environmental friendliness. The production of hydrogen gas using the Proton Exchange Membrane Water Electrolysis (PEMWE) method is considered effective for large-scale production. This study investigates the impact of catalyst loading and various current densities on hydrogen production in the PEM water electrolysis process, utilizing the Cu2O/C catalyst. This study investigates the impact of catalyst loading and different current densities on hydrogen production in the PEM water electrolysis process, utilizing the Cu2O/C catalyst. The electrode catalytic properties were evaluated using the Cyclic Voltammetry (CV) method to determine the Electrochemical Surface Area (ECSA) and the Electrochemical Impedance Spectroscopy (EIS) method to determine the electrical conductivity. The ECSA and EIS measurements demonstrated that the best results were obtained at a higher catalyst loading of 2 mg/cm2 with an ECSA value of 0.21 m2/g and electrical conductivity of 3.04 × 10−6 S/cm. The production of hydrogen results showed that the highest hydrogen production rate was 3.75 mL/s with a catalyst loading of 2.5 mg/cm2, indicating that increasing the load could lead to a higher rate of hydrogen gas production, but this is highly dependent on the surface area utilized. Additionally, at higher current densities, the cell resistance in the electrolysis process may decrease, leading to reduced electrode efficiency for hydrogen production. Thus, the use of high currents may not always be advantageous in hydrogen production using the PEM water electrolysis method.
Pelatihan Pembuatan Salep Untuk Infeksi Kulit dari Ekstrak Daun Karamunting (Rhodomyrtus Tomentosa) Di Desa Tanjung Baru, Ogan Ilir Ferlinahayati, Ferlinahayati; Rachmat, Addy; Hermansyah, Hermansyah; Elfita, Elfita; Hariani, Poedji Loekitowati
Jurnal Altifani Penelitian dan Pengabdian kepada Masyarakat Vol. 4 No. 1 (2024): Januari 2024 - Jurnal Altifani Penelitian dan Pengabdian kepada Masyarakat
Publisher : Indonesian Scientific Journal

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59395/altifani.v4i1.518

Abstract

Kulit memiliki fungsi sebagai pertahanan pertama untuk melindungi tubuh dari penyakit. Infeksi kulit dapat disebabkan oleh mikroorganisme, seperti bakteri, virus, jamur, atau parasit. Tanaman karamunting (Rhodomyrtus tomentosa) secara tradisional telah digunakan masyarakat untuk pengobatan termasuk pengobatan luka. Kegiatan pengabdian masyarakat ini bertujuan memberikan pelatihan pembuatan salep untuk pengobatan infeksi kulit dari ekstrak etanol daun karamunting berbasis vaselin.  Kegiatan pengabdian masyarakat dilakukan di desa Tanjung Baru, kecamatan Indralaya Utara, kabupaten Ogan Ilir. Khalayak sasaran adalah ibu-ibu PKK dan remaja putri sebanyak 30 orang. Tahapan kegiatan yaitu (i) penyuluhan tentang penyakit infeksi kulit, penyebab infeksi kulit, penularan dan pengobatan, (ii) pelatihan pembuatan ekstrak etanol dari daun karamunting, pembuatan salep berbasis vaselin dan (iii) evaluasi hasil kegiatan. Hasil evaluasi kegiatan dengan memberikan berbagai pertanyaan setelah kegiatan menunjukkan 97,62 % peserta menjawab tepat dan sangat tepat materi yang diberikan. Hasil uji tingkat kesukaan dan kenyamanan penggunaan salep menunjukkan sebanyak 82,64 % peserta menyatakan sangat suka terhadap aroma, bentuk, warna, kenyamanan dan daya lekat ketika salep digunakan. Hal ini mengindikasikan bahwa salep untuk infeksi kulit ini diterima dengan baik oleh masyarakat sebagai alternatif pengobatan penyakit infeksi kulit.
Photocatalytic degradation of methylene blue and Congo red dyes from aqueous solutions by bentonite-Fe3O4 magnetic Riyanti, Fahma; Hasanudin, Hasanudin; Rachmat, Addy; Purwaningrum, Widia; Hariani, Poedji Loekitowati
Communications in Science and Technology Vol 8 No 1 (2023)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.8.1.2023.1007

Abstract

This study describes the co-precipitation synthesis of magnetic bentonite-Fe3O4 for photocatalytic degradation of methylene blue and Congo red pigments under visible light. Bentonite-Fe3O4 composites were produced using the mass ratio of 2:1 and 1:1 for bentonite to Fe3O4, respectively. X-ray Powder Diffraction (XRD), Fourier Transform Infra-Red (FTIR), BET surface area, Vibrating-Sample Magnetometer (VSM), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV DRS) were used to characterize the materials. The bentonite-Fe3O4 (1:1) composite exhibited a greater surface area in comparison to the bentonite-Fe3O4 (2:1) composite with a measured value of 106.6 m2/g. It is a superparamagnetic material with a band gap of 2.25 eV and a saturation magnetization of 69.64 emu/g. The photocatalytic degradation of dye using bentonite-Fe3O4 (1:1) with the initial dye concentration of 25 mg/L, volume of 50 mL, catalyst dose of 0.05 g/L, addition of 3 mL H2O2, and 90 minutes of visible irradiation resulted in 94.34% and 98.45% degradation efficiency of methylene blue and Congo red dyes, respectively. The study determined that the most favorable pH for the photocatalytic degradation of methylene blue was pH 11, whereas the optimal pH for Congo red was found at pH 5. For methylene blue and Congo red dyes, photocatalytic degradation followed pseudo-first-order with the constant rates of 0.0356 min-1 and 0.0348 min-1, respectively. After five cycles of use in the photocatalytic process, the catalyst's degradation efficiency fell into below 5%. This research demonstrated that catalysts could be utilized in wastewater treatment technology.
Optimization Photodegradation of Methylene Blue Dye using Bentonite/PDA/Fe3O4@CuO Composite by Response Surface Methodology Riyanti, Fahma; Hariani, Poedji Loekitowati; Hasanudin, Hasanudin; Rachmat, Addy; Purwaningrum, Widia
Bulletin of Chemical Reaction Engineering & Catalysis 2024: BCREC Volume 19 Issue 2 Year 2024 (August 2024)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20132

Abstract

This study aims to synthesize bentonite/PDA/Fe3O4@CuO composites as a catalyst for the photodegradation of Methylene blue dye. Composite characterization involves X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) with X-ray Energy Dispersion Spectrometry (EDS), UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS), and Vibrating Sample Magnetometer (VSM). Response Surface Methodology (RSM) employs Central Composite Design (CCD) to optimize photodegradation by varying dye concentration, irradiation time, and catalyst dose. The bentonite/PDA/Fe3O4@CuO composites exhibit a saturation magnetization value of 54.82 emu/g and a band gap of 2.1 eV. The optimization revealed that concentration and dose significantly impact the photodegradation efficiency. A quadratic model is suitable for modeling the photodegradation of Methylene blue dye using bentonite/PDA/Fe3O4@CuO composites, as determined by analysis of variance (ANOVA). The optimal conditions for achieving maximum photodegradation efficiency were identified as a dye concentration of 10 mg/L, an exposure time of 90 min, and a catalyst dose of 1.67 g/L. Under these parameters, the photodegradation process exhibited a remarkable efficiency of 100%. The Bentonite/PDA/Fe3O4@CuO composites exhibited strong stability, efficiency, and recyclability. After six photodegradation cycles, there was a 5.18% decrease in photodegradation efficiency. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Utilization of Antioxidant Fagraea fragrans fruit as Phytocosmetics Basir, Dasril; Rachmat, Addy; Julinar, Julinar; Eliza, Eliza
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 9, No 1 (2024): February 2024
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24845/ijfac.v9.i1.41

Abstract

The objective is to test the antioxidant activity of methanol (MeOH) extracts,  ethyl acetate (EtOAc) fractions, and an isolated compound of F. fragrans (tembesu) fruitby using DPPH method respectively. Antioxidant is one of the main components of phytocosmetic beside anti-inflammatory, anticancer, and antimicrobial activities while phytocosmetics of F. fragrans fruit is the cosmetics that mainly use extracts or components derived from this fruit only, without preservatives, such as products that do not contain water, oils, dry ointments, or hydro-alcoholic solutions. As a result, The IC50 values of the MeOH extracts, EtOAc fractions, and the isolated compound were 186.5 ± 0.52 microgram/mL, 357.2 ± 0.59 microgram/mL, and 5.658 microgram/mL respectively. The MeOH extracts exhibited moderate antioxidant activity while the isolated compound exhibited strong antioxidant activity. The total flavonoid content of the MeOH extracts and EtOAc fraction was measured by a colorimetric assay, using reagents of 1 M sodium acetic and 10% aluminum chloride. The EtOAc fraction had a total flavonoid content of 4.505 mgQE/g-extract and total phenolic content of 13.732 mgGAE/g-extract while the MeOH extracts had a total flavonoid content of 9.088 mg QE/g-extract and total phenolic content of 23.34 mgGAE/g-extract respectively. Therefore, the utilization of MeOH extracts or the isolated compound of this fruit may be beneficial for developing skincare phytocosmetics and personal care products. Keywords: Phytocosmetics, antioxidant, Fagraea fragrans, tembesu fruit
Hydrogen Production from Aluminum Waste Using the Aluminum-Water Method with Potassium as Activator Amelia, Icha; Rohendi, Dedi; Rachmat, Addy; Syarif, Nirwan; Yulianti, Dwi Hawa; Sya'baniah, Nyimas Febrika; Adhiyanti, Nurmalina; Adelia, Ory; Normah, Normah
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 9, No 2 (2024): June 2024
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24845/ijfac.v9.i2.111

Abstract

Research on hydrogen production from aluminum waste using the aluminum-water method using potassium as an activator has been successfully carried out. This research aims to determine the performance of the potassium activator in hydrogen production with variable water volume and potassium percentage. Hydrogen gas production is carried out using 60 mesh aluminum waste. Optimum conditions were achieved when a mass of 1 gram of aluminum was reacted with an additional volume of water of 1.5 mL, and 7% w/w of the activator mass, with the production of hydrogen gas of 553 mL at a production rate of 69 mL/minute.
Investigation of Mixed MeOH:EtOH Ratio and Air Supply on MEA Performance in Direct Alcohol Fuel Cell (DAFC) Yulianti, Dwi Hawa; Rohendi, Dedi; Majlan, Edy Herianto; Rachmat, Addy; Sya’baniah, Nyimas Febrika
Science and Technology Indonesia Vol. 10 No. 4 (2025): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2025.10.4.1012-1019

Abstract

Methanol (MeOH) and ethanol (EtOH) are commonly used fuels in Direct Alcohol Fuel Cells (DAFC). The advantages of these two fuels are influenced by electrochemical reactions centered around the Membrane Electrode Assembly (MEA). In this study, Pt/C catalyst was used on the cathode and Pt-Ru/C on the anode, with catalyst loadings of 2, 4, 6, 8, and 10 mg/cm2. The anode and cathode were characterized using Cyclic Voltammetry (CV), while the conductivity properties were evaluated through Electrochemical Impedance Spectroscopy (EIS). The Open Circuit Voltage (OCV) of the MEA in a single DAFC cell reached 0.65 V, with the highest value observed at a MeOH:EtOH volume ratio of 70:30 at concentrations of 3 M for MeOH and 2 M for EtOH. In addition to oxidation at the anode, oxygen reduction plays a significant role in the MEA performance on the cathode side. The oxygen supply to the cathode increased the power density by 52.17% at the optimal blower voltage of 5 V.
The Influence of Hydrogen Flow Rate and Humidifier Temperature on Performance of a PEMFC with Ti-Co/C Catalyst Adhiyanti, Nurmalina; Rohendi, Dedi; Utama, Muhammad Prima; Syarif, Nirwan; Rachmat, Addy; Yulianti, Dwi Hawa; Normah, Normah
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 10, No 3 (2025): October 2025
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

This study explores the effect of hydrogen flow rate and humidifier temperature on the performance of the Membrane Electrode Assembly (MEA) using Ti-Co/C catalyst at the cathode and Pt/C at the anode in a single-cell Proton Exchange Membrane Fuel Cell (PEMFC). MEAs were fabricated by the spraying method and characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to determine their electrochemical surface area (ECSA) and conductivity. The results showed that the optimized ECSA value reached 8.38 cm2/g, and the electrical conductivity was 3.76 × 10-8 S/cm. The best performance was achieved at a hydrogen flow rate of 100 mL/min and room temperature humidification. Under the hydrogen flow rate test, the maximum power density reached 0.364 mW/cm2, while in the humidifier temperature variation, a maximum power density of 0.375 mW/cm2  was obtained at a current density 2.4 mA/cm2. These findings suggest that Ti-Co/C is a promising low-cost catalyst alternative to Pt and that operational conditions play a critical role in MEA performance
Preparation of Palm Kernel Shell Binchotan for Radio Frequency Energy Harvesting Sya'baniah, Nyimas Febrika; Syarif, Nirwan; Rohendi, Dedi; Rachmat, Addy; Syahputra, Rio Aldo
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 10, No 3 (2025): October 2025
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Research on the development of radio frequency energy harvesting slabs from palm kernel shells binchotan has been done. The slabs were characterized by using XRD and FTIR intrumentations to determine their crystallography and functional groups. The electrical response of slabs was measured on impedance spectroscopy instrumentation. The conductivity, impedance, and dielectric constant were calculated from impedance spectroscopy data. Diffractograms showed crystalline carbon and confirmed with the existence of peaks, at 2θ, 24.5° and 44.56°. FTIR analysis showed that carbon palm shells have the absorption length is in the range of wave numbers 1100 – 1200 cm-1 for CO of carboxylic acid, aldehyde, ketone and ester, from 1475 to 1600 cm-1 for C=C aromatic ring and double peaks in 1900 – 2100 cm-1 for conjugated C-C. The slabs conductivity varies from 1 to 7 mScm-1. Impedance values for the slabs vary from 1.5 to 2.4 ohm. Dielectric constants for the slabs range from 0.42 to 140.