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All Journal JURNAL KIMIA SAINS DAN APLIKASI Journal of Mathematical and Fundamental Sciences ALCHEMY Jurnal Penelitian Kimia Molekul: Jurnal Ilmiah Kimia

Witri Wahyu Lestari

Chemistry Department, Faculty Of Mathematics And Natural Sciences, Universitas Sebelas Maret, Jl. Ir. Sutami 36A, Surakarta 57126, Jawa Tengah

Author-ID : 3284312

Astronomy Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences Energy Engineering Environmental Science Materials Science & Nanotechnology Mathematics Physics

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Articles

Metal-Organic Frameworks Based on Zinc(II) and Benzene-1,3,5-Tricarboxylate Modified Graphite: Fabrication and Application as an Anode Material in Lithium-Ion Batteries Witri Wahyu Lestari; Wulan Cahya Inayah; Fitria Rahmawati; Larasati Larasati; Agus Purwanto
Journal of Mathematical and Fundamental Sciences Vol. 52 No. 1 (2020)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2020.52.1.6

This research was aimed at synthesizing metal-organic frameworks (MOFs) based on zinc(II) and a benzene-1,3,5-tricarboxylate (BTC) linker in combination with graphite as anode material in lithium-ion batteries. The MOFs were prepared using sonochemical and solvothermal methods, which led to different materials: [Zn3(BTC)2·12H2O] (MOF 1) and [Zn(BTC)·H2O·3DMF] (MOF 2). The produced materials were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric/differential thermal analysis (TG/DTA), and a battery analyzer. Refinement of the XRD data was performed using the Rietica and Le Bail method. Sharp and intense peaks indicated that the materials had a high degree of crystallinity. The morphology of the materials as analyzed by SEM was cubic, with an average crystal size of 8.377 ± 4.276 µm for MOF 1 and a larger size of 16.351 ± 3.683 µm for MOF 2. MOF 1 was thermally stable up to 378.7 °C while MOF 2 remained stable up to 341.8 °C, as demonstrated by thermogravimetric analysis. The employment of the synthesized materials as anode in a lithium ion battery was proved to yield higher specific capacity and cycle stability compared to those using a graphite anode. The lithium-ion battery with 5 wt% MOF 1 exhibited the highest performance with an efficiency of 97.28%, and charge and discharge specific capacities of 123.792 and 120.421 mAh/g, respectively.

Electro-Synthetic Optimization of Host Material Based on MIL-100(Fe) Witri Wahyu Lestari; Joni Hartono; Marisa Adreane; Khoirina Dwi Nugrahaningtyas; Candra Purnawan; Sentot Budi Rahardjo
Molekul Vol 11, No 1 (2016)
Publisher : Universitas Jenderal Soedirman

Electro-synthesis of Metal-Organic Frameworks types of MIL-100(Fe) (MIL = Material Institute of Lavoisier) in ethanol: water (1: 1) with electrolyte TBATFB 0.1 M has been optimized by varying voltage (12, 13, 14 and 15 Volt) and temperature (room temperature, 40, 60 and 80 °C). The product showed light brown powder which upon activation becomes dark brown. Optimum condition achieved during use voltage of 15 Volts and at a temperature of 40 °C with 33% yield. The obtained material was characterized by XRD and compared to CCDC 640536 simulated patterns to confirm the phase purity of the product. As comparison hydrothermal and reflux method have been carried out. Characterization by FTIR has also undertaken to ensure the coordination between the metal cation (Fe3+) and the BTC ligand (BTC = 1,3,5-Benzene Tri Carboxylate). Meanwhile pore analysis using SAA confirmed that MIL-100(Fe) obtained by electrolysis method has a BET surface area reached till 569.191 m²/g with a total pore volume of 0.4540 cc/g and an average pore diameter reached 16 Å. Based on SEM analysis, morphology material show particle size between 0.4-8.6 μm and has a thermal stability up to 350 °C according thermo-gravimetric analysis. Due to the presence of Lewis acid sites on Fe-trimeric unit, porosity features on MIL-100(Fe) and a fairly high thermal stability, this material is potentially used as the host material for the catalyst in the conversion reactions model for green diesel production.

Purification of Carbon-Based Magnetic Nanoparticles (CMNs) Produced by Submerged Arc Discharge in Liquid Ethanol/Ethylenediamine Oktaviana Dyah Mayasari; Dielsa Eka Kuswari; Witri Wahyu Lestari; Teguh Endah Saraswati
Molekul Vol 16, No 1 (2021)
Publisher : Universitas Jenderal Soedirman

Surface modification of covalently amine-attached carbon-based magnetic nanoparticles (CMNs) can be produced quite simply in submerged arc discharge using the amine-containing liquid medium ethylenediamine (ED), resulting in CMNs-ED. However, after the arc discharge processing, the resulting nanoparticles possibly contain physically absorbed amine-containing molecules from a liquid medium on the particle surface. To remove the non-covalently bound molecules, a purification process is required. In this study, the purification was conducted using polar and non-polar solvents following the synthesis process. The surface property was initially characterized by a dispersion test in water, showing that CMNs-ED purified by water have better dispersion than CMNs produced in ethanol alone, CMNs-ED before purification, and CMNs-ED after purification by immersion in toluene. Before and after purification, the diffraction pattern showed definitive peaks corresponded to the crystal planes of C(002), Fe3C(220), and Fe3O4(311) at 26.51°, 44.65°, and 35.42°, respectively. The amine functional group on the nanoparticles before purification thought to come from decomposed ethylenediamine assigned by the vibration peaks appeared at a wavenumbers ~3400 cm-1 and 1020-1220 cm-1, which corresponds to N-H and C-N, respectively. After purification, the vibration peaks of amine groups were still observable, indicating that the amine groups were still covalently attached to the nanoparticles. Magnetic analysis showed that CMNs before and after purification have superparamagnetic properties, with the magnetic saturation value around 10-17 emu/g. The electron microscope images show that the CMNs-ED before purification have a spherical form with a diameter larger than CMNs-ED after purification.

Pengaruh Metode Sintesis secara Solvo-Hidrotermal dan Elektrokimia terhadap Morfologi Struktur HKUST-1 sebagai Katalis Heterogen dalam Reaksi Esterifikasi Asam Palmitat Witri Wahyu Lestari; Joni Hartono; Dian Wahyu Tri Wulansari; Enri Pramuja; Fauziyah Azhari; Triana Kusumaningsih
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 1 (2023): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.1.62466.1-13

Pemilihan metode sintesis akan berpengaruh terhadap karakter material yang dihasilkan yang meliputi kristanilitas, morfologi, luas permukaan, maupun kinerja dalam aplikasinya. Pada penelitian ini telah disintesis HKUST-1 secara solvo-hidrotermal dan elektrokimia dalam pelarut EtOH:H2O (1:1 (v/v)) dan diujicobakan sebagai katalis heterogen dalam esterifikasi asam palmitat. Sintesis secara solvo-hidrotermal, berlangsung dalam autoklaf selama 12 jam pada suhu 120 °C. Sementara itu, sintesis HKUST-1 secara elektrokimia digunakan elektroda tembaga, tegangan sel 15 V selama 90 menit dengan bantuan elektrolit TBATFB pada suhu dan tekanan ambien. Uji katalitik reaksi esterifikasi asam palmitat dilakukan dengan metode refluks selama 2 jam. HKUST-1 hasil sintesis menunjukkan kesesuaian puncak dengan pola difraksi standar CCDC 112954. Hasil refinement menunjukkan HKUST-1 yang diperoleh melalui metode solvo-hidrotermal memiliki kemurnian lebih tinggi. Analisis morfologi menggunakan citra SEM menunjukkan HKUST-1 yang disintesis secara solvo-hidrotermal bergeometri oktahedral sempurna dengan ukuran partikel rata-rata 10,28±1,5 μm, sedangkan HKUST-1 yang disintesis secara elektrokimia berbentuk oktahedral cacat (defect) dengan ukuran partikel rata-rata 4,5±1,6 μm. Analisis termal menunjukkan bahwa HKUST-1 hasil sintesis memiliki stabilitas hingga 300 °C. Uji katalitik dalam reaksi esterifikasi asam palmitat dengan etanol dengan keberadaan katalis HKUST-1 (0,6% berat) menunjukkan peningkatan konversi produk dengan konversi yang paling tinggi ditunjukkan pada HKUST-1 yang disintesis dengan metode elektrokimia (mencapai 43,3%).Effect of Solvo-Hydrothermal and Electrochemical Synthesis Methods on the Structural Morphology of HKUST-1 as a Heterogeneous Catalyst in Palmitic Acid Esterification Reaction. Selection of synthesis method will influence the materials properties including crystallinity, morphology, surface area, and application performance. In this research HKUST-1 was successfully synthesized under solvo-hydrothermal and electrochemical method, and tested as a heterogeneous catalyst in esterification reactions of palmitic acid. Synthesis under solvo-hydrothermal condition was performed in an autoclave at 120 °C for 12h. In addition, the electrochemical synthesis of HKUST-1 using copper electrodes was performed at 15 V in ambient temperature and pressure, for 90 minutes with TBATFB as an electrolyte. The catalytic test in palmitic acid esterification reaction was carried out by reflux for 2h. The HKUST-1 showed conformity with the standard diffraction pattern CCDC 112954. The refinement results shows that solvothermal product has higher purity. Morphological analysis using SEM imaging showed HKUST-1 obtained from solvo-hydrothermal method possess perfect octahedral geometry with average particle size 10.28±1.58 μm, meanwhile electrochemically-synthesized possess a defect octahedral geometry with average particle size 4.5±1.6 μm. Thermal analysis showed that HKUST-1 is stable up to 300 °C. Catalytic test in esterification reaction of palmitic acid with ethanol in the presence of HKUST-1 as catalyst (0.6% wt) showed an enhanced product conversion with highest conversion was achieved in the presence of electrosyntehsized HKUST-1 (up to 43.3%).

Conversion of Wood Waste to be a Source of Alternative Liquid Fuel Using Low Temperature Pyrolysis Method Gesyth Mutiara Hikhmah Al Ichsan; Khoirina Dwi Nugrahaningtiyas; Dian Maruto Widjonarko; Fitria Rahmawati; Witri Wahyu Lestari
Jurnal Kimia Sains dan Aplikasi Vol 22, No 1 (2019): volume 22 Issue 1 Year 2019
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Conversion of wood waste into bio-oil with low temperature pyrolysis method has been successfully carried out using tubular transport reactors. Pyrolysis carried out at temperatures of 250-300°C without using N2 gas. Bio-oil purified by a fractionation distillation method to remove water and light fraction compounds. The materials obtained from different types of wood waste, namely: Randu wood (Ceiba pentandra), Sengon wood (Paraserianthes falcataria), Coconut wood (Cocos nucifera), Bangkirei wood (Shorea laevis Ridl), Kruing wood (Dipterocarpus) and Meranti wood (Shorea leprosula). Bio-oil products are analyzed for their properties and characteristics, namely the nature of density, acidity, high heat value (HHV), and elements contained in bio-oil such as carbon, nitrogen and sulfur content based on SNI procedures, while bio-oil chemical compositions are investigated using Gas Chromatography Mass Spectroscopy (GC-MS). The maximum yield of bio-oil products occurs at 300°C by 40%. Bio-oil purification by fractional distillation method can produce purity of 16-31% wt. The characterization results of the chemical content of bio-oil showed that bio-oil of methyl formate, 2,6-dimetoxy phenol, 1,2,3 trimethoxy benzene, levoglucosan, 2,4-hexadienedioic acid and 1,2- benzenediol.

Co-Authors Candra Purnawan Desi Suci Handayani Dian Maruto Widjonarko Dian Wahyu Tri Wulansari Dielsa Eka Kuswari Eddy Heraldy edi pramono Enri Pramuja Fauziyah Azhari Fitria Rahmawati Fitria Rahmawati Fitria Rahmawati Gesyth Mutiara Hikhmah Al Ichsan I.F. Nurcahyo I.F. Nurcahyo IF Nurcahyo Joni Hartono Joni Hartono Khoirina Dwi N Khoirina Dwi Nugrahaningtiyas Khoirina Dwi Nugrahaningtyas Larasati Larasati Marisa Adreane Oktaviana Dyah Mayasari Purwanto, Agus Qonita Awliya Hanif Reva Edra Nugraha Sentot Budi Rahardjo Teguh Endah Saraswati Triana Kusumaningsih Venty Suryanti Wulan Cahya Inayah Yuniawan Hidayat

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