Claim Missing Document
Check
Articles

Found 31 Documents
Search

Magnetically Separable Fe3O4/SiO2/TiO2 Photocatalyst Composites Prepared through Hetero Agglomeration for the Photocatalytic Degradation of Paraquat Gunlazuardi, Jarnuzi; Fisli, Adel; Ridwan, Ridwan; Krisnandi, Yuni Krisyuningsih; Robert, Didier
Makara Journal of Science Vol. 25, No. 4
Publisher : UI Scholars Hub

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

Abstract

A photocatalyst supported on magnetic material allows the simple technique by using an external magnetic material to separate photocatalyst from the treated water. Thus, it is a magnetically separable nanoparticles photocatalyst (MSNP). The use of superparamagnetic nanoparticles that do not pose spontaneous magnetic moment thus could be dispersed in water and can be recollected easily by an external magnetic bar. We prepare Fe3O4/SiO2/TiO2 composite by hetero agglomeration of Fe3O4/SiO2 and TiO2 at a pH range of 3 to 6.2 in an aqueous slurry.The Fe3O4/SiO2 was prepared via co-precipitation of iron (II) and iron (III) ionic solution containing ammonium hydroxide and sodium silicate. The prepared composites were characterized by XRD, TEM, FTIR, and VSM, while the photocatalytic activities were tested toward paraquat in water. Based on zeta potential values, the Fe3O4/SiO2and TiO2 were being hetero agglomerated at pH 5 to obtain Fe3O4/SiO­2/TiO2 composite. The XRD characterization confirmed the presence of anatase, rutile, and magnetite crystal phases. TEM images showed that the Fe3O4 was covered by SiO2 and randomly attached to TiO2. The observed FTIR peak at 940-960 cm-1 attributed to -Si-O-Ti- bonding mode, ensuring photocatalyst (TiO2) adherence to the Fe3O4/SiO2 cluster. The prepared Fe3O4/SiO2/TiO2 composite showed good photocatalytic activity for the paraquat removal and showed a good magnetic property (VSM measurement)
Review : Sintesis Zeolit dari Bahan Alam dan Limbah Buangan Fitriyah Fitriyah; Yuni Krisyuningsih Krisnandi
Jurnal Serambi Engineering Vol 8, No 3 (2023): Juli 2023
Publisher : Fakultas Teknik

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32672/jse.v8i3.6079

Abstract

Penggunaan zeolit memerlukan biaya yang relatif tinggi untuk sintesis pembuatan zeolitnya. Oleh karena itu perlu adanya alternatif bahan dasar pembuatan zeolit, yang dapat mengurangi biaya preparasi dan sintesis zeolit. Salah satu alternatif sintesis zeolit berasal dari limbah buangan dan bahan alam. Keuntungan lainnya menggunakan bahan alam dan limbah buangan yaitu sebagai salah satu usaha untuk menyelesaikan permasalahan lingkungan.  Berdasarkan jurnal tersebut beberapa bahan menggunakan bahan yang berbeda serta metode dan parameter yang berbeda juga namun menunjukkan hasil sintesis yang signifikan dalam pembuatan zeolit sintesis yang dapat diaplikasikan terhadap lingkungan sebagai adsorben
The Use of Silica Extracted from Kaolin as Catalyst Support for Esterification of 4-Hydroxybenzoic Acid with Sucrose Iman Abdullah; Widayanti Wibowo; Soleh Kosela; Yuni Krisyuningsih Krisnandi
Jurnal Kimia Sains dan Aplikasi Vol 23, No 6 (2020): Volume 23 Issue 6 Year 2020
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2853.986 KB) | DOI: 10.14710/jksa.23.6.196-202

Abstract

SiO2 was extracted from kaolin using concentrated HCl and HNO3 mixture and used as solid support for both Bronsted (HClO4 and H2SO4) and Lewis Acid (AlCl3 and ZnCl2). Before extraction, kaolin was calcined at 800°C for eight hours to form metastable kaolin. After the extraction procedure, silica was recovered in 51.6% yield. Silica and the resulting solid acids were then characterized using XRD, XRF, and FTIR. XRD pattern shows that silica synthesized from kaolin is in the mixture of amorphous and α-quartz silica. Immobilization of acids alters its structure becomes more crystalline. XRF analysis shows that the loading of AlCl3 and ZnCl2 was 9.5 and 24.8%, respectively. The acid catalysts were then used in the esterification reaction of 4-hydroxybenzoic acid with sucrose. The reactions were conducted in dimethyl sulfoxide (DMSO) solvent by varying reaction time and reaction temperature. The highest conversion of starting materials and selectivity towards ester was obtained over the AlCl3/SiO2 catalyst. DPPH radical scavenging test shows that the ester exhibits good antioxidant activity.
Carbon-coated nickel foam for hypochlorous acid sensor Afiten Rahmin Sanjaya; Hanzhola Gusman Riyanto; Isnaini Rahmawati; Yulia Mariana Tesa Ayudia Putri; Dede Nurhalimah; Endang Saepudin; Yudistira Tesla; Yuni Krisyuningsih Krisnandi
Environmental and Materials Vol. 1 No. 1: Juni (2023)
Publisher : Institute for Advanced Science, Social, and Sustainable Future

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61511/eam.v1i1.2023.105

Abstract

The electrochemical detection method of hypochlorous acid (HOCl) using carbon foam electrodes have been successfully developed. The carbon foam was prepared from carbon-coated nickel foam which is synthesized using a hydrothermal-carbonization method. SEM characterization indicated that the optimum synthesis of carbon-coated nickel foam has been achieved on the 4th layer coating process with an expected spherical structure, while characterization using FTIR and Raman spectroscopy confirmed the formation of graphitic material with D band and G band characteristics. An electroactive surface area of ​​0.0236 cm2 was achieved. Cyclic voltammetry of HOCl in 0.1 M phosphate buffer solution pH 6.0 showed the best current response for HOCl reduction occurs at a potential of -0.3 V (vs. Ag/AgCl). Further detection of HOCl using amperometry technique in the concentration range of 2-200 μg/mL showed good linearity with sensitivity of 9.112 mA/µg/L and an estimated detection limit of 1.96 µg/mL. Good repetition is indicated by the RSD value of 2.499 % (n=5). This developed sensor also showed good selectivity in the presence of interference compounds, such as FeCl2 and CuSO4. Besides, the determination of HOCl in tap water has been successfully conducted and generated a comparable result with the UV-VIS method (3.30 µg/mL hypochlorite). The results indicated that the developed sensor is promising for the detection of HOCl in environmental applications.
Nickel-phenanthroline Complex Supported on Mesoporous Carbon as a Catalyst for Carboxylation under CO2 Atmosphere Iman Abdullah; Riri Andriyanti; Dita Arifa Nurani; Yuni Krisyuningsih Krisnandi
Bulletin of Chemical Reaction Engineering & Catalysis 2021: BCREC Volume 16 Issue 1 Year 2021 (March 2021)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.16.1.9733.111-119

Abstract

Carbon dioxide is a highly potential renewable C1 source for synthesis of fine chemicals. Utilization of CO2 in carboxylation reactions requires catalysts, such as: nickel complex for CO2 activation. However, the use of homogeneous catalysts in the reaction is still less efficient due to the difficulty of separating the product and catalyst from reaction mixture. Therefore, it is necessary to heterogenize the nickel complex in a solid support such as mesoporous carbon. In this report, mesoporous carbon (MC) prepared from phloroglucinol and formaldehyde through soft template method was used as a solid support for Ni-phenanthroline complex (Ni-phen). The catalyst was characterized by Fourier Transform Infra Red (FT-IR), X-Ray Diffraction (XRD), Scanning Electron Microscope - Energy Dispersive X-Ray (SEM-EDX), and Surface Area Analyzer (SAA). The result of SAA characterization showed that the pore diameter of MC was 6.7 nm and Ni-phen/MC was 5.1 nm which indicates that the materials have meso-size pores. Ni-phen/MC material was then used as a heterogeneous catalyst in the carboxylation reaction of phenylacetylene under an ambient CO2 pressure. The reactions were carried out in several variations of conditions such as temperature, time and catalyst types. Based on the results of the reaction, the best conditions were obtained at 25 °C for 8 h of reaction time using Ni-phen/MC catalyst.  Copyright © 2021 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). 
Synthesis and Characterization of Mesoporous Carbon Supported Ni-Ga Catalyst for Low-Pressure CO2 Hydrogenation Uwin Sofyani; Yuni Krisyuningsih Krisnandi; Iman Abdullah
Bulletin of Chemical Reaction Engineering & Catalysis 2022: BCREC Volume 17 Issue 2 Year 2022 (June 2022)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.17.2.13377.278-285

Abstract

In this study, the atmospheric-pressure hydrogenation of CO2 was carried over bimetallic Ni-Ga catalyst supported on mesoporous carbon (MC). MC was successfully prepared using the soft-template method as proven by Fourier Transform Infra Red (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy - Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Brunauer–Emmett–Teller  Surface Area Analyzer (BET SAA), and Transmission Electron Microscopy (TEM) characterizations. The Ni-Ga/MC catalyst was synthesized using the impregnation method, and based on the XRD characterization, the formation of bimetallic Ni-Ga on the MC support is confirmed. The EDS mapping image shows the uniform distribution of the bimetallic Ni-Ga on the MC surface, especially for the Ni5Ga3/MC and NiGa3/MC catalysts. Moreover, the TEM images show an excellent pore size distribution. The formation of Ni-Ga alloy was identified as an active site in the CO2 hydrogenation. Ni5Ga3/MC catalyst exhibited a 10.80% conversion of CO2 with 588 μmol/g formaldehyde at 1 atm, 200 °C, and H2/CO2 ratio of 3/1. 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). 
Effect of Physicochemical Properties of Co and Mo Modified Natural Sourced Hierarchical ZSM-5 Zeolite Catalysts on Vanillin and Phenol Production from Diphenyl Ether Anita Nur Ramadhani; Iman Abdullah; Yuni Krisyuningsih Krisnandi
Bulletin of Chemical Reaction Engineering & Catalysis 2022: BCREC Volume 17 Issue 1 Year 2022 (March 2022)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.17.1.13372.225-239

Abstract

The conversion of lignocellulose biomass to value-added chemicals is challenging. In this paper, the conversion process of diphenyl ether (DPE) as a model lignin compound to phenol and vanillin compounds involved a bifunctional catalyst in reaching the simultaneous one-pot reaction in mild conditions with a high yield product. The catalysts used in this conversion are hierarchical ZSM-5 zeolites and their cobalt oxide and molybdenum oxide impregnated derivate. The ZSM-5 zeolites were synthesized using alternative precursors from natural resources, i.e., Indonesian natural zeolite and kaolin. The physicochemical properties of the catalysts were determined with various characterization methods, such as: X-ray Diffraction (XRD), Fourier Transform Infra Red (FT-IR), Scanning Electron Microscope - Energy Dispersive X-ray (SEM-EDX), X-ray Fluorescence (XRF), Surface Area Analyzer (SAA), and NH3-Temperature Programmed Desorption (NH3-TPD). The catalytic activity on conversion of DPE substrates showed that the MoOx/HZSM-5 produced the highest %yield for phenol and vanillin products; 31.96% at 250 °C and 7.63% at 200 °C, respectively. The correlation study between the physicochemical properties and the catalytic activity shows that the dominance of weak acid (>40%) and mesoporosity contribution (pore size of ~ 9 nm) play roles in giving the best catalytic activity at low temperatures. 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). 
Review : Sintesis Zeolit dari Bahan Alam dan Limbah Buangan Fitriyah Fitriyah; Yuni Krisyuningsih Krisnandi
Jurnal Serambi Engineering Vol 8, No 3 (2023): Juli 2023
Publisher : Fakultas Teknik

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32672/jse.v8i3.6079

Abstract

Penggunaan zeolit memerlukan biaya yang relatif tinggi untuk sintesis pembuatan zeolitnya. Oleh karena itu perlu adanya alternatif bahan dasar pembuatan zeolit, yang dapat mengurangi biaya preparasi dan sintesis zeolit. Salah satu alternatif sintesis zeolit berasal dari limbah buangan dan bahan alam. Keuntungan lainnya menggunakan bahan alam dan limbah buangan yaitu sebagai salah satu usaha untuk menyelesaikan permasalahan lingkungan.  Berdasarkan jurnal tersebut beberapa bahan menggunakan bahan yang berbeda serta metode dan parameter yang berbeda juga namun menunjukkan hasil sintesis yang signifikan dalam pembuatan zeolit sintesis yang dapat diaplikasikan terhadap lingkungan sebagai adsorben
Antibacterial Testing on Silver/Zinc Oxide Nanoparticles/Organoclay Reinforced Chitosan Biocomposites Muiz, Lisna Junaeni; Juwono, Ariadne Lakshmidevi; Paputungan, Zulkarnaen; Krisnandi, Yuni Krisyuningsih
Makara Journal of Science Vol. 27, No. 3
Publisher : UI Scholars Hub

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

Abstract

Herein, bionanocomposites of chitosan (CS)/silver nanoparticle/organoclay/zinc oxide nanoparticle (CS/Ag/OC/ZnO) were prepared for antibacterial food packaging. This study examines the time variation in the AgNP synthesis method by comparing local (74˗85% deacetylated) and commercial chitosan (75%˗85% deacetylated) as a reducing and capping agent and seeks to reconstruct the optimum ratio formulations of AgNPs and ZnONPs in bionanocomposites for food packaging. The results reveal that the synthesis of AgNPs was successfully carried out using a local chitosan solution as a reducing and capping agent. The CS/Ag/OC/ZnO films exhibit structural, mechanical, and optical properties suitable for food packaging and antibacterial activity on Staphylococcus aureus and Escherichia coli. The relative inhibition zone increased with increasing numbers of AgNPs and ZnONPs. The inhibition zone values indicated that E. coli and S. aureus bacteria were sensitive to the film, namely 12.5 ± 1.5 mm, and 16 ± 0.0 mm, respectively.
Modification of Indonesian Kaolinite-Based Silica Coarse (SC) for RNA Extraction Method of SARS-CoV-2 Marintan, Marchia Marthalena; Sjatha, Fithriyah; Nurani, Dita Arifa; Krisnandi, Yuni Krisyuningsih; Sariman, Sariman
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.2024.9.2.325-335

Abstract

One of the strategies to overcome the COVID-19 disease is through rapid diagnostic tests using the Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) test. The RT-PCR test is a detection and quantification test of nucleic acids, initiated by the pre-analytical step of purification of the nucleic acids. Purification of nucleic acid requires silica-based materials as a solid phase-extraction matrix or column. Herein, Silica Coarse (SC) in the form of suspension and powder columns; was prepared from natural Indonesian Kaolinite as an alternative extraction column to binding RNA of SARS-CoV-2. The RNA binding and releasing ability in SC was enhanced with the support of chaotropic agents in the form of Na+ and Guanidium+ as charged balancing cations, embedded in the silicate layer inside the kaolinite framework. SC, which has been supported with Na+ and Guanidium+ respectively, then studied its physicochemical characteristics using FTIR spectroscopy, X-ray diffraction technique, scanning electron microscopy, and BET surface area and pore size measurement. This work shows that the modified SC suspension column could extract RNA of SARS-CoV-2 that amplified better in the RT PCR test than SC powder columns, with the initial Ct value of all the SARS-CoV-2 specimens in the range < 20.
Co-Authors Adam, Martin Adel Fisli Afiten Rahmin Sanjaya Ahmed, Sabeel Alika Rizki Anggraeni Anastasia Agnes Andita Junia Mulyadi Anita Nur Ramadhani Anya Prilla Azaria Arnia Putri Pratama Arnia Putri Pratama Atia, Hanan Bayu Adi Samodro Dede Nurhalimah Dita Arifa Nurani Duha Rushida Amanullah Eckelt, Reinhard Ekananda, Rizki ENDANG SAEPUDIN Endang Saepudin, Endang Fahriansyah, Irsan Fitriyah Fitriyah Griffith, Benyamin E Hanna, John Vincent Hanzhola Gusman Riyanto Hedi Surahman Idra Herlina Iman Abdullah Irena Khatrin Isnaini Rahmawati Jarnuzi Gunlazuardi Juwono, Ariadne Lakshmidevi Khanifah Khanifah Khatrin, Irena Luthfiyah, Siti Zahrotul Marintan, Marchia Marthalena Martin, Andreas Muhammad Faisal Muhammad Ridwan Muiz, Lisna Junaeni 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 Rahayu, Dyah Utami Cahyaning Rahma Widya Rahma Widya Rahmat Wibowo Rahmawati, Isnaini Ralentri Pertiwi Richter, Manfred Ridwan, Ridwan Rika Tri Yunarti 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 Howe, Russell Francis Sabeel Ahmed Sanjaya, Afiten Rahmin Saragi, Indah Revita Sariman Sariman Savitri Octaviani Siti Zahrotul Luthfiyah SJATHA, FITHRIYAH Soleh Kosela Supriyono Supriyono Supriyono Tengku Riza Zarzani N Tesla, Yudistira Uwin Sofyani Widayanti Wibowo Widhyasmaramurti Widya, Rahma Yudistira Tesla Yulia Mariana Tesa Ayudia Putri