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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

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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)
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). 
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

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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.
Carbon-coated nickel foam for hypochlorous acid sensor Sanjaya, Afiten Rahmin; Riyanto, Hanzhola Gusman; Rahmawati, Isnaini; Putri, Yulia Mariana Tesa Ayudia; Nurhalimah, Dede; Saepudin, Endang; Tesla, Yudistira; Krisnandi, Yuni Krisyuningsih
Environmental and Materials Vol. 1 No. 1: (June) 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.
Amine-modified Ni-DOBDC MOF for CO2 capture: CO2 adsorption capacity and reusability Fahriansyah, Irsan; Khatrin, Irena; Abdullah, Iman; Krisnandi, Yuni Krisyuningsih
Environmental and Materials Vol. 2 No. 2: (December) 2024
Publisher : Institute for Advanced Science, Social, and Sustainable Future

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61511/eam.v2i2.2024.1431

Abstract

Background: Anthropogenic carbon dioxide (CO₂) emissions have risen significantly due to the extensive use of fossil fuels, necessitating the development of effective CO₂ capture and conversion techniques. Adsorption using Metal-Organic Frameworks (MOFs) has shown great potential due to their high CO₂ adsorption capacity, particularly Ni-based MOFs. Enhancing their adsorption efficiency remains a key research focus to improve sustainability in CO₂ capture applications. Methods: Ni-based MOF (Ni-DOBDC) was synthesized using the solvothermal method, employing DMF as the solvent and 2,5-dihydroxyterephthalic acid (DOBDC) as the organic ligand. To enhance CO₂ adsorption capacity, Ni-DOBDC was further modified with ethylenediamine (EDA) via post-synthetic modification. Structural characterization was performed using XRD, confirming similarity to the Ni-DOBDC reference (CCDC 288477), and FTIR, which showed enhanced absorbance peaks. SEM-EDX analysis revealed a flower-like morphology with an average particle size of 0.75 μm. CO₂ adsorption tests were conducted on Ni-DOBDC and EDA/Ni-DOBDC (10%) using the titration method under controlled conditions. Findings: The CO₂ adsorption capacity of Ni-DOBDC and EDA/Ni-DOBDC was tested at 70°C with a CO₂ concentration of 50% in N₂. EDA modification significantly improved CO₂ adsorption capacity, with EDA/Ni-DOBDC achieving 9.95 mmol g⁻¹ compared to pristine Ni-DOBDC’s 6.44 mmol g⁻¹. However, Ni-DOBDC exhibited better regeneration ability in a three-cycle reusability test, likely due to EDA leaching during regeneration. Conclusion:  EDA-modified Ni-DOBDC demonstrates enhanced CO₂ adsorption capacity, making it a promising material for CO₂ capture applications. However, its reduced regeneration stability suggests the need for further optimization to improve long-term performance. Future studies should explore strategies to minimize EDA leaching while maintaining high adsorption efficiency. Novelty/Originality of this article: This study provides new insights into improving Ni-based MOF performance for CO₂ capture through post-synthetic modification with EDA. The findings highlight a trade-off between increased adsorption capacity and material stability, emphasizing the need for further refinement in MOF functionalization strategies.
Harnessing Copper's Potential: A Review of Cu-Based Catalysts for Glycerol Conversion Ahmed, Sabeel; Abdullah, Iman; Krisnandi, Yuni Krisyuningsih
Bulletin of Chemical Reaction Engineering & Catalysis 2025: BCREC Volume 20 Issue 2 Year 2025 (August 2025)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20341

Abstract

The increasing depletion of fossil fuel reserves and environmental concerns have accelerated the search for sustainable alternatives, leading to the utilization of biodiesel as a renewable energy source. Glycerol, a key byproduct of biodiesel production, has been extensively investigated for conversion into value-added compounds such as lactic acid, acrylic acid, and 1,2-propanediol (1,2-PDO). Copper-based catalysts have gained popularity due to their low cost, high catalytic efficiency, and environmental friendliness. This review examines various copper-based catalytic systems for glycerol conversion through key processes such as hydrogenolysis, oxidation, steam reforming, and dehydration. The work focuses on how Cu-based bimetallic catalysts, such as Cu-Ni, Cu-Co, and Cu-Zn, improve reaction selectivity and conversion rates via synergistic interactions, better metal dispersion, and optimized redox properties. Furthermore, new catalyst manufacturing methods, such as ammonia evaporation, hydrothermal, and ion exchange approaches, have shown improved stability and reusability. The findings show that Cu-based catalysts successfully facilitate high glycerol conversion, with selective pathways favouring the generation of 1,2-PDO, lactic acid, and acrylic acid under optimal circumstances. However, catalyst deactivation caused by sintering and coke formation remains a concern. Future research should concentrate on creating stable, multifunctional catalysts, adding bio-derived support, and improving reaction conditions to increase long-term efficiency and industrial usability. This review emphasizes the potential of Cu-based catalytic systems in promoting glycerol valorisation and achieving a more sustainable chemical industry. Copyright © 2025 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).
Strategic Synthesis of Hierarchical Co3O4/ZSM-5 Zeolite as A Catalyst in Partial Oxidation of Methane: Bottom-up vs Top-down Methods Khatrin, Irena; Putri, Danika Nurranalya; Ridwan, Muhammad; Krisnandi, Yuni Krisyuningsih
Bulletin of Chemical Reaction Engineering & Catalysis 2025: BCREC Volume 20 Issue 3 Year 2025 (October 2025)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20441

Abstract

Methane, a potent greenhouse gas contributing approximately 19% to global warming and possessing a global warming potential 28 times greater than carbon dioxide, necessitates conversion into more beneficial chemicals. Partial oxidation of methane to methanol is a promising conversion method which is both time- and cost-efficient. This study synthesized ZSM-5 using two strategic syntheses: Bottom-Up and Top-Down, followed by cobalt oxide impregnation at varying percentages 2.5, 5, and 10% (w/w) to produce Co3O4/ZSM-5. To investigate its physicochemical properties, ZSM-5 catalysts were thoroughly characterized with XRD, FTIR, XRF, N2-physisorption, and SEM. These catalysts were then evaluated in methane partial oxidation reactions conducted in a batch reactor, with a CH4:N2 feed ratio of 0.75 bar:2 bar, at 150 °C for 60 minutes. Co3O4-supported Bottom-Up ZSM-5 with 5% Co-loading demonstrated the largest percentage yield of 62.08% compared to the other Co-loading amount and ZSM-5 synthesized via Top-Down method. Copyright © 2025 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).