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All Journal Jurnal Sains Materi Indonesia Science and Technology Indonesia Indonesian Journal of Chemistry Jurnal Abdidas Makara Journal of Science Environmental and Materials Bulletin of Chemical Reaction Engineering & Catalysis

Yuni Krisyuningsih Krisnandi, Yuni Krisyuningsih

Department Of Chemistry, FMIPA, Universitas Indonesia, Depok

Author-ID : 1133084

Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Control & Systems Engineering Education Energy Engineering Environmental Science Health Professions Materials Science & Nanotechnology Mathematics Physics Public Health Social Sciences Other

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PHOTOCURRENT ENHANCEMENT OF CdS QUANTUM DOT SENSITIZED TiO2 ELECTRODE IN THE PRESENCE OF GOLD NANO PARTICLES Supriyono Supriyono; Hedi Surahman; Yuni Krisyuningsih Krisnandi; Jarnuzi Gunlazuardi
Jurnal Sains Materi Indonesia Vol 16, No 3: APRIL 2015
Publisher : Center for Science & Technology of Advanced Materials - National Nuclear Energy Agency

PHOTOCURRENT ENHANCEMENT OF CdS QUANTUM DOT SENSITIZED TiO2 ELECTRODE IN THE PRESENCE OF GOLD NANO PARTICLES. Photo current enhancement of CdS Quantum Dot (CdS-QD) sensitized TiO2 electrode in the presence of gold nano particles had been investigated. CdS quantum dots were prepared by successive ionic layer adsorption and reaction (SILAR) method, in which solution containing Cd(CH3COO)2 and Na2S were used as a precursor. Where as, gold nano particles was synthesized using solution containing HAuCl4 as a precursor, NaBH4 as a reducing agent and polyvinyl pyrrolydone (PVP) as a stabilizer. The film of CdS quantum dots and Au nano particles were characterized by UV-Vis spectrophotometer, Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), and electro chemical working station. Photo electrochemical study revealed that CdS-sensitized TiO2 electrode with gold nanoparticles have been able to increase photocurrent of 54 A/cm2 to 68 A/cm2, so the photocurrent enhancement of approximately 25% was observed. This observation indicates that the gold nanoparticles is potentially applicable to enhance photocurrent in a CdS-QD sensitized TiO2 electrode, which may lead to the development of more efficient solar cell.

Penggunaan Teknologi dalam Pelatihan Pembuatan Sabun sebagai Upaya Pemberdayaan Santri Pesantren Darussalam - Sumenep di Masa Pandemi Covid-19 Widhyasmaramurti Widhyasmaramurti; Khanifah Khanifah; Yuni Krisyuningsih Krisnandi
Jurnal Abdidas Vol. 2 No. 1 (2021): February, Pages 1-160
Publisher : Universitas Pahlawan Tuanku Tambusai

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31004/abdidas.v2i1.232

Pandemi Covid-19 yang melanda seluruh dunia berimbas ke berbagai ranah kehidupan masyarakat. Efek Covid-19 juga dirasakan oleh para santri Pesantren Darussalam Sumenep. Di masa pandemi ini, para santri dihadapkan pada pilihan kembali ke rumah atas desakan ekonomi, atau tetap bertahan di pesantren. Santri yang bertahan di pesantren perlu mematuhi protokol kesehatan yaitu mencuci tangan, memakai masker dan menjaga jarak. Hal ini menyebabkan kebutuhan sabun dalam lingkungan pesantren meningkat. Maka pelatihan pembuatan sabun dilakukan dengan tujuan sebagai upaya pemberdayaan masyarakat untuk mendukung pencegahan Pandemi Covid-19 dalam lingkup pesantren, namun tetap memiliki nilai ekonomi di saat yang bersamaan. Adanya Pembatasan Sosial Berskala Besar (PSBB) di daerah-daerah di Indonesia tidak membuat pelatihan pembuatan sabun terhenti karena teknologi tepat guna digunakan sebagai alternatif pelatihan pembuatan sabun. Pelatihan secara sinkronus dengan menggunakan platform Zoom, video demonstrasi pembuatan sabun yang terakses melalui media daring seperti YouTube, serta pendampingan kontinu oleh koordinator lapangan menjadi alternatif pelatihan di masa pandemi ini. Kurang stabilnya akses jaringan internet menjadi tantangan yang ditindaklanjuti melalui forum diskusi (chat) menggunakan WhatsApp. Proses evaluasi menggunakan Focus Group Discussion (FGD) dan Google Form menjadi sarana melihat indikator keberhasilan. Hasil pengabdian masyarakat ini ada dua, yaitu: 1) tertransfernya pengetahuan pembuatan sabun melalui teknologi tepat guna, 2) terbentuknya komunitas santri yang mampu memproduksi sabun. Walaupun produksi sabun masih bersifat untuk konsumsi internal pesantren, namun santri Pesantren Darussalam diharapkan mampu membangun jaringan penjualan sabun sebagai upaya peningkatan ekonomi mereka. Pemberdayaan masyarakat ini juga diharapkan dapat membentuk komunitas santri yang mampu mendukung pemerintah dalam upaya mencegah Covid-19.

Direct Synthesis of Methanol by Partial Oxidation of Methane with Oxygen over Cobalt Modified Mesoporous H-ZSM-5 Catalyst Yuni Krisyuningsih Krisnandi; Bayu Adi Samodro; Riwandi Sihombing; Russell Francis Howe
Indonesian Journal of Chemistry Vol 15, No 3 (2015)
Publisher : Universitas Gadjah Mada

Partial oxidation of methane over mesoporous catalyst cobalt modified H-ZSM-5 has been carried out. Mesoporous Na-ZSM-5 (Si/Al = 35.4) was successfully synthesized using double template method which has high surface area (450 m2/g) and average pore diameter distribution of 1.9 nm. The as-synthesized Na-ZSM-5 was converted to H-ZSM-5 through multi-exchange treatment with ammonium ion solution, causing decreased crystallinity and surface area, but increased porous diameter, due to dealumination during treatment process. Moreover, H-ZSM-5 was loaded with cobalt (Co = 2.5% w) by the incipient impregnation method and calcined at 550 °C. Partial oxidation of methane was performed in the batch reactor with 0.75 bar methane and 2 bar of nitrogen (with impurities of 0.5% oxygen) as the input at various reaction time (30, 60 and 120 min). The reaction results show that cobalt species in catalyst has an important role, because H-ZSM-5 cannot produce methanol in partial oxidation of methane. The presence of molecular oxygen increased the percentage of methanol yield. The reaction is time-dependent with the highest methanol yield (79%) was acquired using Co/H-ZSM-5 catalyst for 60 min.

Hierarchical MnOx/ZSM-5 as Heterogeneous Catalysts in Conversion of Delignified Rice Husk to Levulinic Acid Yuni Krisyuningsih Krisnandi; Dita Arifa Nurani; Anastasia Agnes; Ralentri Pertiwi; Noer Fadlina Antra; Alika Rizki Anggraeni; Anya Prilla Azaria; Russell Francis Howe
Indonesian Journal of Chemistry Vol 19, No 1 (2019)
Publisher : Universitas Gadjah Mada

Hierarchical ZSM-5 zeolite was synthesized using a double template method using TPAOH and PDDA as templates, while microporous ZSM-5 was also prepared using only TPAOH as a template. The syntheses then were followed by impregnation with Mn(II) c.a. 2 wt.% and calcination at 550 °C to obtain MnOx/ZSM-5 zeolite catalysts. Extensive characterization of the zeolite catalysts was performed using XRD, SEM, AAS, EDX, FTIR and BET measurement. The characterization showed that hierarchical or mainly mesoporous ZSM-5 was successfully synthesized, having added features compared to the microporous counterpart. The catalysts then were used in conversion reaction of delignified rice husk to levulinic acid, a platform chemical. As a comparison, a certain amount of MnCl2.4H2O was used as a homogeneous catalyst in a similar reaction. The product of the reaction was separated and analyzed with HPLC. It showed that 8 h was the optimum condition for the conversion, with hierarchical MnOx/hi_ZSM-5 catalyst gave the highest amount of levulinic acid (%Y of 15.83%), followed by microporous MnOx/mi_ZSM-5 (%Y of 10%). The % yield of levulinic acid using homogeneous Mn(II) catalyst (%Y of 8.86%) gave more charcoal as a product. Meanwhile, the stability of the zeolite catalysts after the reaction has also been investigated, mainly by analyzing the FTIR spectra and EDX data of the used catalysts after separated and calcined at 550 °C. From the analysis, some of the silica and alumina are leached from the framework, as well as the manganese oxide due to acidic condition at the beginning of the reaction. Nevertheless, it can be concluded that the conversion took place as the interaction between the cellulose and either MnOx in zeolites or Mn2+ ions in the solution, with the support of porous ZSM-5 framework. Hierarchical system somehow assists the ZSM-5 structure stays intact.

Synthesis and Characterization of Copper Impregnated Mesoporous Carbon as Heterogeneous Catalyst for Phenylacetylene Carboxylation with Carbon Dioxide Putri Nurul Amalia; Iman Abdullah; Dyah Utami Cahyaning Rahayu; Yuni Krisyuningsih Krisnandi
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.52778

Carbon dioxide (CO2) is a compound that can potentially be used as a carbon source in the synthesis of fine chemicals. However, the utilization of CO2 is still constrained due to its inert and stable nature. Therefore, the presence of a catalyst is needed in CO2 conversion. This study aims to synthesize copper impregnated mesoporous carbon (Cu/MC) as a catalyst for phenylacetylene carboxylation reaction with CO2 to produce phenylpropiolic acid. The synthesis of mesoporous carbon was performed via the soft template method. The as-synthesized Cu/MC material was characterized by FTIR, SAA, XRD, and SEM-EDX. BET surface area analysis of mesoporous carbon showed that the material has a high surface area of 405.8 m2/g with an average pore diameter of 7.2 nm. XRD pattern of Cu/MC indicates that Cu has been successfully impregnated in the form of Cu(0) and Cu(I). Phenylacetylene carboxylation reaction with CO2 was carried out by varying reaction temperatures (25, 50, and 75 °C), amount of catalyst (28.6, 57.2, and 85.8 mg), type of base (Cs2CO3, K2CO3, and Na2CO3), and variation of support. The reaction mixtures were analyzed by HPLC and showed that the highest phenylacetylene conversion of 41% was obtained for the reaction at 75 °C using Cs2CO3 as a base.

Adsorption of Phosphate Ion in Water with Lithium-Intercalated Gibbsite Sihombing, Riwandi; Krisnandi, Yuni Krisyuningsih; Widya, Rahma; Luthfiyah, Siti Zahrotul; Yunarti, Rika Tri
Makara Journal of Science Vol. 19, No. 4
Publisher : UI Scholars Hub

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In order to enhance adsorption capacity of gibbsite (Al(OH)3 as an adsorbent for the adsorption of phosphate in water, gibbsite was modified through lithium-intercalation. The purification method of Tributh and Lagaly was applied prior to intercalation. The Li-Intercalation was prepared by the dispersion of gibbsite into LiCl solution for 24 hours. This intercalation formed an cationic clay with the structure of [LiAl2(OH)6]+ and exchangeable Cl- anions in the gibbsite interlayer. A phosphate adsorption test using Lithium-intercalated gibbsite (LIG) resulted in optimum adsorption occurring at pH 4.5 with an adsorption capacity of 11.198 mg phosphate/g LIG which is equivalent with 1.04 wt% LIG. The adsorption capacity decreased with decreasing amounts of H2PO4-/HPO4- species in the solution. This study showed that LIG has potential as an adsorbent for phosphate in an aqueous solution with pH 4.5–9.5.

Fe(III) Oxide-modified Indonesian Bentonite for Catalytic Photodegradation of Phenol in Water Pradisty, Novia Arinda; Sihombing, Riwandi; Howe, Russell Francis; Krisnandi, Yuni Krisyuningsih
Makara Journal of Science Vol. 21, No. 1
Publisher : UI Scholars Hub

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Phenol, which is a major organic pollutant, is usually detected in industrial wastewater, and thus the wastewater should be processed further before discharged into water bodies. Application of heterogeneous catalysis using natural-basedmaterials is known to be effective and environmentallyfriendlyinremoving hazardous substances in water. In this study, local natural bentonite from the Tapanuli region in Indonesia was modified to eliminate dissolved phenol. Elimination by photodegradation reaction was conductedinaphoto-Fenton system utilizing Fe(III) oxide-modifiedbentonite (Fe-B) as catalyst. Fe-B was prepared byacation exchanging process using mixture solutions of NaOH and FeCl3 with OH/Femolar ratio of 2:1 and calcined at 300 °C. Material characterization was performed by X-ray diffraction (XRD), low-angle XRD, Fourier transform infrared spectroscopy and atomic absorption spectroscopy. The reaction components consisted of ultraviolet Clight, H2O2, and Fe-B, and they were processed in a batch reactor. The role of each component was analyzed by a series of reaction conditions (i.e., adsorption, photolysis, H2O2effect, Fenton, and homogeneous photo-Fenton). The heterogeneous photo-Fenton system was found to be essential for phenol degradation, as none of the reaction conditions caused total phenol removal in the 180 min reaction time. To conclude, heterogeneous photo-Fenton gave the highest photodegradation activity, and the best experimental condition for 1.10 mM phenol removal was 5 g L-1 catalyst, 78.35 mM H2O2, and 90 minreaction time.

Grass-Like Structured Mesoporous Carbon as an Acid Red 119 Dye Adsorbent Krisnandi, Yuni Krisyuningsih; Priantini, Tania; Faisal, Muhammad; Yunarti, Rika Tri; Saragi, Indah Revita; Gunlazuardi, Jarnuzi
Makara Journal of Science Vol. 23, No. 4
Publisher : UI Scholars Hub

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Grass-like structured mesoporous carbon was prepared by the soft-template method using triblock copolymer Pluronic F127, affording an organic–organic composite structure between phloroglucinol and formaldehyde. Thermogravimetric analysis revealed that the as-synthesized mesoporous carbon is stable to 900 °C, and X-Ray Diffraction (XRD) analysis confirmed the presence of carbon material structures at 2θ values of 22.020° and 42.420°. A hysteresis loop at relative partial pressures (P/Po) between 0.45 and 0.85 was observed in the N2 adsorption isotherm, indicating that the solid material exhibits mesoporous characteristics, with a homogeneous pore size distribution of 8.863 nm. Scanning Electron Microscope (SEM) images revealed that the bulk carbon surface exhibits a uniform grass-like structure. Furthermore, the as-synthesized mesoporous carbon was investigated for the adsorption of a diazo dye Acid Red 119, and it exhibited an adsorption capacity of 217.7389 mg/g; this capacity is 1.53 times greater than that of commercial activated carbon. Therefore, this mesoporous carbon is a potential adsorbent for the treatment of synthetic coloring waste.

ZnO/SiO2 Composite as Catalyst for the Transformation of Glycerol to Glycerol Carbonate Krisnandi, Yuni Krisyuningsih; Eckelt, Reinhard; Atia, Hanan; Adam, Martin; Saragi, Indah Revita; Martin, Andreas; Richter, Manfred
Makara Journal of Science Vol. 24, No. 1
Publisher : UI Scholars Hub

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Zinc oxide/porous silica (ZnO/SiO2) composite was used as a catalyst to transform glycerol to glycerol carbonate (GC), a chemical intermediate and monomer for the synthesis of new functionalized polymers. The ZnO/SiO2 catalyst was prepared using the direct precipitation method by mixing zinc sulfate solution with Aerosil 300 silica suspension and adding potassium oxalate solution. Catalytic transformation used glycerol and urea (molar ratio = 1:1) at 140 °C, 40 mbar, and various reaction times (1–6 h). The ZnO catalyst exhibited a high percentage of glycerol conversion of 82.38%; however, the yield of GC and selectivity toward GC were relatively low (i.e., 33.33% and 40.46%, respectively). The presence of silica support (ZnO/(x)SiO2 increased the selectivity toward GC and yield of GC to 74.40% to 77.83% and 57.86% to 64.30%, respectively. Furthermore, although its crystallinity decreased, the reused ZnO/(60)SiO2 catalyst still exhibited a high activity. The scanning transmission electron microscopy image indicated the migration of ZnO on the surface of the composite and the possibility of ZnO-glycolate formation, which were also confirmed by FTIR measurement. Nevertheless, these results showed that ZnO/SiO2 is a promising catalyst for the transformation of glycerol to GC.

Natural Aluminosilicate-based Y Zeolite for Catalytic Cracking of n-Hexadecane Khatrin, Irena; Saragi, Indah Revita; Ekananda, Rizki; Hanna, John Vincent; Griffith, Benyamin E; Krisnandi, Yuni Krisyuningsih
Makara Journal of Science Vol. 24, No. 2
Publisher : UI Scholars Hub

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Natural zeolite and kaolin are abundant in Indonesia especially in Java and Belitung islands. These materials generally contain high aluminosilicate minerals that can be used as silica and alumina sources for the formation of NaY zeolite. This research aimed to identify the modification of NaY zeolite structure using Bayat natural zeolite as alumina source and Belitung kaolin as silica source and its catalytic activity for n-hexadecane cracking. Pretreatment of materials were performed in several steps: activation, purification, fragmentation for Bayat–Klaten natural zeolite, and silica extraction for Belitung kaolin. The synthesis of NaY was performed hydrothermally using seed-assisted method with crystallization times of 24 and 48 h. The surface area analysis showed a typical surface area of microporous zeolite (i.e., a pore diameter of 1.897 nm) and surface area of 309.4 cm2/g. Meanwhile, powder X-ray diffraction characterization showed that the as-synthesized materials have the structure of NaY zeolite. The optimum crystallization time was 24 h with Si/Al ratio of 4.10. Furthermore, both synthetic and natural sourced NaY zeolites were converted into HY zeolites and employed as cracking catalyst of n-hexadecane in a fixed-bed reactor at 500 °C for 75 s. The natural sourced HY resulted in 59.80% conversion and 59.80% yield of gasoline product (C9–C12). These values were lower than the results given by synthetic HY (80%).

Co-Authors Adam, Martin Adel Fisli Ahmed, Sabeel Alika Rizki Anggraeni Amanullah, Duha Rushida Anastasia Agnes Anita Nur Ramadhani Anya Prilla Azaria Atia, Hanan Bayu Adi Samodro Dita Arifa Nurani Eckelt, Reinhard Ekananda, Rizki Endang Saepudin, Endang Fahriansyah, Irsan Griffith, Benyamin E Hanna, John Vincent Hanzhola Gusman Riyanto Hedi Surahman Herlina, Idra Iman Abdullah Iman Abdullah Iman Abdullah Jarnuzi Gunlazuardi Juwono, Ariadne Lakshmidevi Khanifah Khanifah Khatrin, Irena Luthfiyah, Siti Zahrotul Marintan, Marchia Marthalena Martin, Andreas Muhammad Faisal Muhammad Ridwan Muiz, Lisna Junaeni Mulyadi, Andita Junia Noer Fadlina Antra Novia Arinda Pradisty Nurani, Dita Arifa Nurhalimah, Dede Paputungan, Zulkarnaen Pradisty, Novia Arinda Pratama, Arnia Putri Priantini, Tania Putri Nurul Amalia Putri, Danika Nurranalya Putri, Yulia Mariana Tesa Ayudia Rahayu, Dyah Utami Cahyaning Rahma Widya Rahma Widya RAHMAT WIBOWO Rahmawati, Isnaini Ralentri Pertiwi Richter, Manfred Ridwan, Ridwan Rika Tri Yunarti Riri Andriyanti Riwandi Sihombing Riwandi Sihombing Riwandi Sihombing Riwandi Sihombing Riwandi Sihombing, Riwandi Robert, Didier Russell Francis Howe Russell Francis Howe Russell Francis Howe Russell Francis Howe, Russell Francis Sanjaya, Afiten Rahmin Saragi, Indah Revita Sariman Sariman Savitri Octaviani Siti Zahrotul Luthfiyah SJATHA, FITHRIYAH Supriyono Supriyono Tengku Riza Zarzani N Tesla, Yudistira Uwin Sofyani Widhyasmaramurti Widya, Rahma Yunarti, Rika Tri

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