Article Per Year (5 Year)
p-Index From 2021 - 2026
3.354
P-Index
This Author published in this journals
All Journal CHEMISTRY PROGRESS Indonesian Journal of Chemical Science Science and Technology Indonesia Indonesian Journal of Chemistry Communications in Science and Technology IJEMS (Indonesian Journal of Environmental Management and Sustainability) Molekul: Jurnal Ilmiah Kimia Sains dan Matematika SRIWIJAYA JOURNAL OF ENVIRONMENT Makara Journal of Science Makara Journal of Technology Bulletin of Chemical Reaction Engineering & Catalysis Indonesian Journal of Material Research Prosiding Seminar Nasional Unimus
Risfidian Mohadi
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Sriwijaya University, Kampus UNSRI Indralaya, Jl. Palembang Prabumulih Km 32 Ogan Ilir 30662, South Sumatera
Agriculture, Biological Sciences & Forestry Humanities Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Decision Sciences, Operations Research & Management Electrical & Electronics Engineering Energy Engineering Environmental Science Health Professions Materials Science & Nanotechnology Mathematics Mechanical Engineering Nursing Physics Public Health

Published : 37 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 37 Documents
Search

 1   2   3   4 
STUDI KINETIKA DAN TERMODINAMIKA ADSORPSI TEMBAGA (II) MENGGUNAKAN ADSORBEN KITIN-SELULOSA HASIL IMPREGNASI Lesbani, Aldes; Agustina, Sherly; Hidayati, Nurlisa; Mohadi, Risfidian
Indonesian Journal of Chemical Science Vol 4 No 1 (2015)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v4i1.4762

Abstract

Telah dilakukan proses impregnasi kitin dari cangkang bekicot dan selulosa dari jerami padi menggunakan tiourea sebagai impregnan. Hasil impregnasi dikarakterisasi menggunakan spektrofotometer FTIR yang dibandingkan dengan spektra FTIR kitin maupun selulosa sebelum impregnasi. Selanjutnya hasil impregnasi kitin-selulosa digunakan sebagai adsorben pada adsorpsi tembaga(II). Proses adsorpsi dipelajari melalui parameter kinetika dan termodinamika dan dibandingkan dengan kitin dan selulosa sebelum impregnasi. Hasil penelitian menunjukkan bahwa proses impregnasi berhasil dilakukan yang ditunjukkan adanya bilangan gelombang baik untuk kitin maupun selulosa pada spektra FTIR. Hasil penentuan parameter kinetika menunjukkan proses adsorpsi mengikuti order laju reaksi adsorben hasil impregnasi (0,006 menit-1)  > kitin (0,005 menit-1) > selulosa (0,004 menit-1). Penentuan parameter termodinamika yang diamati dari kapasitas adsorpsi menunjukkan order kapasitas adsorpsi pada adsorben hasil impregnasi (5x10-4 mol/g) > kitin (2,5x10-4 mol/g) > selulosa (0,63x10-4 mol/g).
Production of Adipic Acid from Mixtures of Cyclohexanol-Cyclohexanone using Polyoxometalate Catalysts Lesbani, Aldes; Sumiati,; Mardiyanto,; Fithri, Najma Annuria; Mohadi, Risfidian
Makara Journal of Science Vol. 19, No. 2
Publisher : UI Scholars Hub

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

Abstract

Adipic acid production through catalytic conversion of cyclohexanol-cyclohexanone using polyoxometalate H5[a-BW12O40] and H4[a-SiW12O40] as catalysts was carried out systematically. Polyoxometalates H5[a-BW12O40] and H4[a-SiW12O40] were synthesized using an inorganic synthesis method and were characterized using Fourier transform infrared spectroscopy (FTIR). Adipic acid was formed from conversion of cyclohexanol-cyclohexanone and was characterized by using melting point measurement, identification of functional group using FTIR spectrophotometer, analysis of gas chromatography-mass spectrometry (GC-MS), and 1H and 13C NMR (nuclear magnetic resonance) spectrophotometer. This research investigated the influence of reaction time and temperature on the conversion. The results showed that adipic acid was formed successfully with a yield of 68% by using H5[a-BW12O40] as the catalyst with a melting point of 150-152 °C after optimization. In contrast, using H4[a-SiW12O40] as the catalyst, the formation was only 3.7%. Investigation of time and temperature showed 9 h as the optimum reaction time and 90 °C as the optimum temperature for conversion of up to 68%. Identification using FTIR, 1H, and 13C NMR showed that the adipic acid from conversion of cyclohexanol-cyclohexanone was in agreement with the standard adipic acid data in the literatures. GC-MS analysis indicated that several by-products were formed in conversion of cyclohexanol-cyclohexanone using H5[a-BW12O40] and H4[a-SiW12O40] as the catalysts.
Preparation of Zn/Al-chitosan Composite for the Selective Adsorption of Methylene Blue Dye in Water Mohadi, Risfidian; Siregar, Patimah Mega Syah Bahar Nur; Palapa, Neza Rahayu; Lesbani, Aldes
Makara Journal of Science Vol. 26, No. 2
Publisher : UI Scholars Hub

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

Abstract

Layered double hydroxide (LDHs) are widely used adsorbents for methylene blue removal. However, LDHs have a perishable structure that cannot be used repeatedly. Modifying LDHs with chitosan produces a strong material with a large surface area for methylene blue adsorption. Adsorption conditions were optimized by determining the adsorption isotherms and the adsorbent regeneration process. Results showed that the adsorption process was balanced in 90 min with maximum adsorption capacities of 86.207 mg/g, 35.336 mg/g, and 98.039 mg/g for Zn/Al, chitosan, and Zn/Al-chitosan, respectively. The adsorption in this study followed the Freundlich isotherm model. Regeneration analysis of the adsorbent showed that Zn/Al-chitosan can be used repeatedly in methylene blue adsorption.
Characterization and Utilization of Calcium Oxide (CaO) Thermally Decomposed from Fish Bones as a Catalyst in the Production of Biodiesel from Waste Cooking Oil Lesbani, Aldes; Sitompul, Sabat Okta Ceria; Mohadi, Risfidian; Hidayati, Nurlisa
Makara Journal of Technology Vol. 20, No. 3
Publisher : UI Scholars Hub

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

Abstract

Thermal decomposition of fish bones to obtain calcium oxide (CaO) was conducted at various temperatures of 400, 500, 800, 900, 1000, and 1100 °C. The calcium oxide was then characterized using X-ray diffractometer, FTIR spectrophotometer, and SEM analysis. The calcium oxide obtained from the decomposition at 1000 °C was then used as a catalyst in the production of biodiesel from waste cooking oil. Diffraction pattern of the calcium oxide produced from decomposition at 1000 °C showed a pattern similar to that of the calcium oxide produced by the Joint Committee on Powder Diffraction Standard (JCDPS). The diffractions of 2q values at 1000 °C were 32.2, 37.3, 53.8, 64.1, and 67.3 deg. The FTIR spectrum of calcium oxide decomposed at 1000 °C has a specific vibration at wave-length 362 cm-1, which is similar to the specific vibration of Ca-O. SEM analysis of the calcium oxide indicated that the calcium oxide’s morphology shows a smaller size and a more homogeneous structure, compared to those of fish bones. The use of calcium oxide as a catalyst in the production of biodiesel from waste cooking oil resulted in iod number of 15.23 g/100 g KOH, density of 0.88 g/cm3, viscosity of 6.00 cSt, and fatty acid value of 0.56 mg/KOH. These characteristic values meet the National Standard of Indonesia (SNI) for biodiesel.
Synthesis of Tris(4-Methoxyphenyl)Phenylsilane Using Phenylsilane and 4-Iodo Anisole Catalyzed by Palladium Complex Lesbani, Aldes; Mohadi, Risfidian; Eliza, Eliza; Mardiyanto, Mardiyanto
Makara Journal of Science Vol. 8, No. 1
Publisher : UI Scholars Hub

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

Abstract

Sintesis Tris(4-Metoksifenil)Fenilsilan Menggunakan Fenilsilan dan 4-Iodida Anisol dengan Katalis Senyawa Kompleks Paladium. Sintesis tris(4-metoksifenil)fenilsilan melalui reaksi kopling antara fenilsilan dan 4-iodida anisol menggunakan senyawa paladium tersier tributilfosfin sebagai katalis telah dilakukan berdasarkan penentuan senyawa basa, pelarut, dan waktu reaksi kopling. Hasil penelitian menunjukkan bahwa senyawa tris(4-metoksifenil)fenilsilan dapat disintesis menghasilkan persentase produk maksimum pada penggunaan senyawa 1,4-diazabisiko[2,2,2]oktan (DABCO) sebagai basa, tetrahidrofuran sebagai pelarut, dan waktu reaksi kopling selama 5 hari. Persentase tertinggi produk senyawa tris(4-metoksifenil)fenilsilan adalah 35%.
Synthesis of Tris(4-Methoxyphenyl)Phenylsilane Using Phenylsilane and 4-Iodo Anisole Catalyzed by Palladium Complex Lesbani, Aldes; Mohadi, Risfidian; Eliza, Eliza; Mardiyanto, Mardiyanto
Makara Journal of Science Vol. 18, No. 1
Publisher : UI Scholars Hub

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

Abstract

Sintesis Tris(4-Metoksifenil)Fenilsilan Menggunakan Fenilsilan dan 4-Iodida Anisol dengan Katalis Senyawa Kompleks Paladium. Sintesis tris(4-metoksifenil)fenilsilan melalui reaksi kopling antara fenilsilan dan 4-iodida anisol menggunakan senyawa paladium tersier tributilfosfin sebagai katalis telah dilakukan berdasarkan penentuan senyawa basa, pelarut, dan waktu reaksi kopling. Hasil penelitian menunjukkan bahwa senyawa tris(4-metoksifenil)fenilsilan dapat disintesis menghasilkan persentase produk maksimum pada penggunaan senyawa 1,4-diazabisiko[2,2,2]oktan (DABCO) sebagai basa, tetrahidrofuran sebagai pelarut, dan waktu reaksi kopling selama 5 hari. Persentase tertinggi produk senyawa tris(4-metoksifenil)fenilsilan adalah 35%.
Removal of Methyl Orange in Aqueous Medium using ZnO/Bentonite as Semiconductor by Photocatalytic Process Priatna, Satria Jaya; Yuliana, Ayu; Zulkarnain; Melwita, Elda; Arsyad, Fitri Suryani; Mohadi, Risfidian
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.2024.9.3.539-545

Abstract

Pillarization of bentonites (from East Java) with ZnO semiconductors has been synthesized using co-precipitation methods into a ZnO/Bentonite composite and applied as a catalyst in a photocatalytic process to remove Methyl Orange (MO) dyes. The optimum pH condition of MO dyes is at pH 2 with a degradation rate of 22.91% (from 15 mg/L to 11.523 mg/L). The optimum ZnO/Bentonite catalyst weight condition is 200 mg, with a degradation rate of 29.11% (from 15 mg/L to 10.596 mg/L). The optimum time condition for UV lamp irradiation is 60 minutes, with a degradation rate of 64.92% (from 15 mg/L to 5.244 mg/L). The kinetics of MO photocatalytic reaction using ZnO/Bentonite catalyst follows the pseudo-first-order Langmuir Hinshelwood-Santosa kinetic model with photocatalytic reaction rate constant (k1) of 0.014 and photocatalytic equilibrium constant (K) of 0.012.
Selective Removal of Anionic and Cationic Dyes Using Magnetic Composites Fitri, Erni Salasia; Mohadi, Risfidian; Palapa, Neza Rahayu; Susila Arita Rachman; Lesbani, Aldes
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.129-136

Abstract

Water is one of the most basic human needs, and dyes are one of the sources of water pollution. Since adsorption has proven to be effective in removing contaminants, it is the most widely used technique. In this adsorption, a LDH Zn-Al /magnetic biochar composite was used for dye removal. Zn-Al LDH, magnetic biochar, and LDH Zn-Al/biochar magnetic composite were successfully synthesized, based on XRD and FTIR studies. XRD analysis of the Zn-Al LDH material shows diffractions of (003), (006), (101), (012), (015), (107), and (110) around the 2theta angle at 10.29°, 20.07°, 29.59°, 32.12°, 34.02°, 48.06°, and 60.16° which are characteristic of LDH materials. In magnetic biochar and LDH Zn-Al/magnet biochar composites diffraction (220), (311), (422) and (440) at 2theta around 24.9°, 35°, 63° and 68.4° in these materials indicate the characteristics of carbon-based materials from biochar. FTIR analysis showed the appearance of a vibration peak at 1404cm−1 indicating the presence of C H groups contained in biochar. The characteristic double-layer hydroxy (M-O) vibrations below 1000 cm−1 also indicated that the composite preparation process had been successful. The study’s results show that cationic dyes are more easily adsorbed than anionic dyes. Specifically, the LDH Zn-Al/Magnetic Biochar composite more extensively absorbs the cationic dye malachite green.
High Performance of Ni-Al/magnetite Biochar for Methyl Orange Removal in Aqueous Solution Palapa, Neza Rahayu; Zahara, Zaqiya Artha; Mohadi, Risfidian; Royani, Idha; Lesbani, Aldes
Science and Technology Indonesia Vol. 9 No. 1 (2024): January
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.2024.9.1.156-166

Abstract

Elevated concentrations of dyes in water have a significant impact on both the aquatic ecosystem and human well-being. The adsorption approach, which is cost-effective and simple to use, was chosen for color treatment. The adsorbents used in this study were Modified Layered Double Hydroxides (LDHs) and Magnetite Biochar (MBC). To prepare the Ni-Al/MBC composites, a technique called coprecipitation and hydrothermal was employed. The successful preparation of these composites was confirmed through the use of characterization tests including X-Ray Diffraction (XRD), Fourier Transform – Infra Red (FT-IR), Brunauer Emmet Teller (BET), and Vibrating Sample Magnometer (VSM). The study focused on analyzing the kinetics, isotherms, and thermodynamics of adsorption in order to anticipate the mechanism of Methyl Orange (MO) adsorption. Additionally, the regeneration process was investigated to assess the adsorbent's ability for repeated usage. The percentage of Ni-Al/MBC adsorbed during the first to fifth regeneration cycles was 86.940%, 82.545%, 70.752%, 56.244%, and 34.503% respectively. The duration of contact was 70 minutes, as determined by the Pseudo Second Order (PSO) equation, with an adsorption rate of 0.0030 g/mg.min. The Langmuir equation indicated a maximum adsorption capacity of 45.455 mg/g.
ZnAl LDH-based Derivative Materials as Photocatalysts: Synthesis, Characterization, and Catalytic Performance in Tetracycline Degradation Rohmatullaili; Ahmad, Nur; Erviana, Desti; Zultriana; Savira, Dila; Mohadi, Risfidian; Lesbani, Aldes
Science and Technology Indonesia Vol. 9 No. 2 (2024): April
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.2024.9.2.457-469

Abstract

Layered Double Hydroxide (LDH)-derived materials exhibited different characteristics from LDH precursors. The conversion of ZnAl LDH into its derivative material has been carried out to find the best catalyst for TC degradation. ZnAl (LDH)-based catalysts in this study have been effectively synthesized using coprecipitation, calcination, and restacking procedures. ZnAl Layered Double Oxide (LDO) is derived from the calcination of ZnAl LDH at 500°C. ZnAl LDH was also modified by adding Garcinia mangostana pericarp extract (GME). XRD, FT-IR, UV-DRS, and SEM-EDX were used to investigate the synthesized catalyst. ZnAl LDH exhibited the typical LDH FT-IR spectra, whereas ZnAl LDO showed metal oxide-like spectra, and the ZnAl-GME composite displayed the combination spectra of precursor material. The ZnAl LDH XRD diffraction pattern exhibited the attributes of a layered material, whereas the other three catalysts did not. Calcination destroyed the layered structure of ZnAl LDH, whereas the addition of GME to LDH and LDO generated a single-layered composite. The modified ZnAl-GME composite showed a decrease in both particle size and bandgap energy. At an ideal pH of 5, the synthesized catalyst was used in a batch system photodegradation of 5 mg/L Tetracycline (TC), employing solar light irradiation. ZnAl LDO holds the most significant catalytic activity and structural stability through the fifth regeneration cycle, degraded TC up to 100% in 90 minutes.
Co-Authors Agustiarini, Vitry Aldes Lesbani Alfarizi, Muhammad Afif Amri Amri Amri Andreas, Roy Apriani, Elsa F. Arsyad, Fitri Suryani Badri, Arini Fousty Broekaert, José A.C. Elfita Elfita . Eliza . Eliza Eliza Erviana, Desti Fahma Riyanti Fitri, Erni Salasia Hakim, Yusuf Mathiinul Hanifah, Yulizah Hesti A. Harahap, Hesti Idha Royani Jefri Jefri Juleanti, Novie Karvenia, Icha Aulia Kiki Anggraini, Kiki Komala Syari Kurniawan, Gilang Lingga, Fitra Wahyuni Mardianto Mardiyanto Mardiyanto Mardiyanto Mardiyanto, Melwita, Elda MUHAMAD UMAR HARUN Mustafa Kamal Najma Annuria Fithri, Najma Annuria Normah Normah Normah Normah, Normah Nova Yuliasari Nur Ahmad Nur Ahmad, Nur Nur khakim, Mokhamad Yusup Nurlisa Hidayati Prayitno, Muhammad Bambang Ramadhan, Jeri Rohmatullaili Rohmatullaili, Rohmatullaili Sabat Okta Ceria Sitompul, Sabat Okta Ceria Sari, Wida Fatma Satria Jaya Priatna, Satria Jaya Savira, Dila Sherly Agustina, Sherly Siregar, Patimah Mega Syah Bahar Nur Siti Sailah, Siti Sri Haryati Suheryanto SUMIATI, Supriyadi Supriyadi Susila Arita Tarmizi Taher Wardhana, Singgih Tri Wibiyan, Sahrul Wijaya, Alfan Yosi Saria Yosine Susie Yuliana, Ayu Zahara, Zaqiya Artha Zulkarnain Zultriana