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All Journal Science and Technology Indonesia Jurnal Riset Teknologi Pencegahan Pencemaran Industri Makara Journal of Science Environmental and Materials
Yoki Yulizar
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Control & Systems Engineering Energy Engineering Environmental Science Materials Science & Nanotechnology Physics

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Microwave-Assisted Synthesis of Alginate-Stabilized Gold Nanoparticles Foliatini, Foliatini; Yulizar, Yoki; Hafizah, Mas Ayu Elita
Makara Journal of Science Vol. 18, No. 4
Publisher : UI Scholars Hub

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Abstract

during boreal summer to fall 2011. In this study, data from satellite observations and atmospheric reanalysis datasets
Investigation on the Synergistic Complexation of Ni(II) with 1,10-Phenanthroline and Dithizone at Hexane-Water Interface Using Centrifugal Liquid Membrane-SpectrophotometryInvestigation on the Synergistic Complexation of Ni(II) with 1,10-Phenanthroline and Dithizone at Hexane-Water Interface Using Centrifugal Liquid Membrane-Spectrophotometr Yulizar, Yoki; Wahyuningsih, Nerny; Asri, Novena Damar; Watarai, Hitoshi
Makara Journal of Science Vol. 16, No. 3
Publisher : UI Scholars Hub

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Complex formation of Ni(II) and 1,10-phenanthroline (C12H8N2/Phen) with the addition of dithizone (C13H12N4S/HDz) at the hexane-water interface has been studied by direct measurement spectrophotometry using the centrifugal liquid membrane (CLM) method. Ni(II) ion with Phen formed a cationic complex of Ni(C12H8N2)2 2+ or NiPhen2 2+. That complex dissolved in the aqueous phase and had two UV absorption spectrum maxima wavelengths, λmax 270 and 292 nm. Observation of complex formation was performed variations of pH and ligand concentration. The pH caused protonation that affected the amount of the formed complex. With the variations of ligand concentrations, the greater was the concentration of ligands the greater was the formed complex. Based on the Batch method, the HDz ligand addition into the NiPhen2 2+ cationic complex produced ion association complex of Ni(C13H11N4S)2(C12H8N2) or NiDz2Phen at λmax 403 nm, and was extracted in the organic phase. Measurement results using CLM method showed that NiDz2Phen complex was formed at hexane-water interface with λmax 523 nm. Comparison of Phen with HDz ligand concentrations affected the initial formation rate of NiDz2Phen complex. The greater concentration of Phen ligand increased the initial rate of formation for synergistic complex. The obtained data using CLM method indicated that the synergistic complex formation rate constant of NiDz2Phen at the interface, k was 0.30/s.
Synthesis of gold nanoparticles with allicin to modify boron-doped diamond surface for oxygen sensor applications Raharto, Toto; Setiyanto, Cahya Mukti; Ariyanta, Harits Atika; Nahda, Dinda Prastika Nabila; Hani, Adinda Muthia; Yulizar, Yoki; Ivandini, Tribidasari Anggraningrum; Einaga, Yasuaki
Environmental and Materials Vol. 1 No. 2: (December) 2023
Publisher : Institute for Advanced Science, Social, and Sustainable Future

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61511/eam.v1i2.2023.560

Abstract

Modification of surface of boron-doped diamond (BDD) film with gold nanoparticles (AuNPs) was carried out to increase its catalytic activity for an application as an oxygen sensor. Allicin was isolated from garlic by salting out extraction technique, and then used as the capping agent to synthesize AuNPs as it has a double bond structure that could be reacted to attach the BDD surface under UV light radiation. An average size of AuNPs at around 46,00 ± 9,06 nm was obtained, while the modification of the BDD surface by the synthesized AuNPs indicated that the surface of BDD could be covered by gold at around 0.6 % (w/w). Investigation of the AuNPs-modified BDD as a working electrode for the oxygen reduction by using cyclic voltammograms in 0.1 M phosphate buffer solution pH 7 observed a current peak at around -0.45 V (vs. Ag/AgCl). The current of this peak linearly increased proportionally to the dissolved oxygen concentrations (R2=0.9986). Moreover, a limit of detection of the dissolved oxygen of 0.12 ppm and limit of quantity 0.41 ppm could be achieved with excellent stability at 6.86% RSD with 6 repetitions and sensitivity at 19.086 μA/ppm indicated that the modified BDD is promising for applications as an oxygen sensor.
Preparation and Characterization of ZnO-Fe2O3 Nanocomposite Using Green Synthesis Method and Its Application in Powder Pyrotechnics Lestariana, Evie; Supriyatno, Heru; Sitompul, Hamonangan Rekso Diputro; Restasari, Afni; Yulizar, Yoki
Science and Technology Indonesia Vol. 10 No. 2 (2025): 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.2025.10.2.493-503

Abstract

Nanocomposites are often used as a catalyst in the pyrolysis of Al/Mg/KNO3 rocket igniter charge. Because the synthesis of the nanocomposites has a negative impact on the environment, in this study, the nanocomposite of ZnO-Fe2O3 was synthesized using a green synthesis method based on the aqueous fraction of Syzygium polyanthum (Wight) Walp. leaf extract. The secondary metabolites contained in the extract were tested. ZnO-Fe2O3 nanocomposite was characterized using Ultra-Violet-Visible Diffuse Reflectance Spectroscopy (UV Vis-DRS), Fourier Transform Infra-Red Spectroscopy (FT-IR), X-ray Diffraction (XRD), Particle Size Analyzer (PSA), Scanning Electron Microscope-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), and Transmission Electron Microscope (TEM).The thermal decomposition process of Al/Mg/KNO3 with and without ZnO-Fe2O3 nanocomposite was analyzed using Differential Thermal Analysis (DTA) and Thermogravimetry Analysis (TGA). As a result, ZnO-Fe2O3 nanocomposite is successfully synthesized, proven by UV-Vis DRS, FT-IR, XRD, and SEM-EDS analysis. It highlights the effectiveness of aqueous leaves extract of Syzygium polyanthum (Wight) Walp. as a capping agent because of the secondary metabolites. Based on PSA and TEM characterization, the particle size is 17.37 nm. The TGA curves demonstrate that the addition of ZnO-Fe2O3 nanocomposite lowers the activation energy for decomposition of Al/Mg/KNO3, from 58.71 kJ/mol to 52.07 kJ/mol, as well as reduces the stage in the decomposition process. A particular reason lies on the role of ZnO-Fe2O3 nanocomposite in reducing the activation energy of the thermal decomposition ofKNO3.
Easy Preparation of Zinc Molybdate Photocatalyst and Its Application for Degradation of Methylene Blue Bakri, Ridla; Firmansyah, Rika; Yulizar, Yoki
Jurnal Riset Teknologi Pencegahan Pencemaran Industri Vol. 14 No. 2 (2023): November
Publisher : Balai Besar Standardisasi dan Pelayanan Jasa Pencegahan Pencemaran Industri

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21771/jrtppi.2023.v14.no2.p45-53

Abstract

Photocatalyst is one way that can be done to overcome the problem of dye waste in water. Hazardous chemicals are regularly used in the manufacture of photocatalysts. In this research, ZnMoO4 was prepared by an environmentally friendly and cost-effective synthesis. The functional groups, crystalline structure and morphology of ZnMoO4 were characterised using fourier transform infrared (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The band gap energy has been studied through UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic activity of ZnMoO4 was tested against the organic pollutant methylene blue under visible light irradiation and its degradation products were analyzed with a UV-Vis spectrophotometer at a wavelength of 664 nm. The photocatalytic process of ZnMoO4 has been able to degrade 99% of methylene blue after 80 minutes of irradiation. The excellent photodegradation performance indicates that the transition activity of electron currents from the valence band to the conduction band on ZnMoO4 is going well.
Co-Authors Aida R. Pudjiastuti Asri, Novena Damar Destia Puteri Ananda, Destia Dewi Tristantini Dianursanti Einaga, Yasuaki Eny Kusrini Firmansyah, Rika Foliatini Foliatini Hani, Adinda Muthia Harits Atika Ariyanta Heru Supriyatno Ivandini Tribidasari Anggraningrum Lestariana, Evie Mas Ayu Elita Hafizah Nahda, Dinda Prastika Nabila Ng Sha Shiong Raharto, Toto Restasari, Afni Ridla Bakri Rita Arbianti Setiyanto, Cahya Mukti Sitompul, Hamonangan Rekso Diputro Slamet . Tresye Utari, Tresye Virleenda M. Setianingrum Wahyuningsih, Nerny Watarai, Hitoshi Yosmarina Harahap