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SYNTHESIS AND CHARACTERIZATION OF NANOSILICA (SiO2) VOLCANIC ROCK OF MOUNT BATUR IN BALI Artha, I Komang Restu Widi; Mardana, Ida Bagus Putu; Arjana, I Gede
Indonesian Physical Review Vol. 7 No. 2 (2024)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v7i2.310

Abstract

This research was conducted to synthesize and characterize silica minerals (SiO2) from volcanic rocks in the active volcano in Bali, namely Mount Batur. The synthesis carried out on five different color variants of this rock sample is by the coprecipitation method which begins with the process of taking rock samples on Mount Batur, crushing the rock until it becomes powder with a size of 100 mesh, washing with distilled water and drying, immersing the rock powder in the solution. 2 M HCl for 12 hours, then the results of the soaking were reacted again with 7 M NaOH solution as a hydrolysis process to obtain pure SiO2 in the sample. In the form of sodium silicate precursor (Na2SiO3), the sample was titrated with a 2 M HCl solution to obtain silica gel which was then washed and dried until amorphous silica powder was produced. The results of the XRF analysis showed that the SiO2 mineral content in the sample after going through the synthesis process was 94.9% and the Si element was 89.9%. The XRD characterization results show that the phase formed from the sample has a quartz structure with the highest peak at an angle of 2θ = 23.07o, then decreases and levels out at an angle of 2θ = 32.94o which is characteristic of an amorphous structure and with a silica grain size of 8.47 nm – 8.65 nm.
SYNTHESIS OF MAGNETITE NANOPARTICLES (Fe3O4) BASED ON TAMAN RIVER SAND MAGNETIC MINERALS Agung, Gusti Kade Agung Widiantara; Mardana, Ida Bagus Putu; Arjana, I Gede
Indonesian Physical Review Vol. 7 No. 3 (2024)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v7i3.314

Abstract

This research aims to produce Fe3O4 magnetic nanoparticles-based Taman River sand as the raw material through coprecipitation. The Fe content percentage in the Taman River sand after separation was characterized using XRF testing. The lattice parameters and crystal size of the samples were tested using XRD. The nanoparticles' morphology, structure, particle shape, and elemental content were characterized using SEM-EDX. The magnetic properties and magnetic saturation values were tested using VSM. XRF testing results on the iron sand showed a Fe content of 84.72%. The synthesis resulted in a brNownish-black Fe3O4 nanoparticle powder that a permanent magnet could attract. Based on the XRD results, the Fe3O4 nanoparticle powder peaks were obtained at X-ray diffraction pattern angles of 2θ: 21.44°, 35.38°, 41.74°, 50.78°, 63.36°, 67.70°, and 74.66°, indicating the presence of Fe3O4 nanoparticles. The crystal structure formed was cubic with lattice parameters a = b = c = 8.331 Å and a crystal size of 18.43 nm. SEM-EDX results showed an average particle size of 25-30 nm. VSM results indicated that the Fe3O4 sample had a saturation magnetization (Ms) of 27.36 emu/g, a remanent magnetization (Mr) of -0.01 emu/g, and a coercive field (Hc) of 0.01 T.
SYNTHESIS AND CHARACTERIZATION OF MAGNETITE NANOMATERIALS IN TIANYAR IRON SAND USING CO-PRECIPITATION METHOD Kristina, Ni Putu Devi; Arjana, I Gede; Yasa, Putu
Indonesian Physical Review Vol. 7 No. 3 (2024)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v7i3.328

Abstract

In the current era of scientific and technological progress, nanomaterials have emerged as a deeply fascinating and significant field of research. This paper presents a case study on the synthesis and characterization of Fe₃O₄ nanomaterials derived from the iron sand of the Tianyar, utilizing the co-precipitation method with modifications made to the pH values during synthesis. The research encompasses three primary stages: extraction of iron sand, synthesis of Fe3O4 nanomaterials, and subsequent characterization of these nanomaterials. The iron sand extraction phase involved passing it through a permanent magnet ten times to remove impurities. Subsequent synthesis produced a dark black magnetite nanomaterial powder displaying magnetic properties, rendering it responsive to magnet attraction. Analysis of these nanomaterials using X-ray diffraction (XRD) unveiled discernible peaks in the diffraction pattern, suggesting that the magnetite nanomaterials possess a cubic crystal structure. The size of the Fe3O4 nanomaterials decreases as the pH of precipitation increases, with respective sizes of approximately 18.00 nm for pH 9, 14.69 nm for pH 10, and around 13.68 nm for pH 11, as determined using Scherrer’s formula. The lattice parameters observed for samples synthesized at pH 9, 10, and 11 are sequentially measured as a = 8.59 Å, 8.81 Å, and 8.80 Å. Analysis using SEM-EDS revealed that the sample morphology appears rough, with evidence of particle agglomeration leading to uneven particle distribution. There are additional trace elements present, including C, Al, S, Ti, and Cl, albeit in smaller quantities. Nevertheless, the primary elements crucial for forming Fe3O4 nanomaterials, namely Fe and O, exhibit the highest percentages in composition analysis.
Sulfidation of Iron - Based Nanomaterial as Catalyst for Water Splitting Using Hydrothermal Lestari, Ni Luh Ayu Ardi; Arjana, I Gede; Mardana, Ida Bagus Putu
Journal of Comprehensive Science Vol. 3 No. 5 (2024): Journal of Comprehensive Science (JCS)
Publisher : Green Publisher Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59188/jcs.v3i5.728

Abstract

Consumption of fossil fuels causes greenhouse effect and global warming, hence the need for renewable energy sources that are environmentally friendly. Hydrogen is one of the abundant elements on earth. Hydrogen refers to a clean and renewable energy source, hydrogen can be a good choice to reduce greenhouse gas emissions. One way to produce hydrogen is by electrochemical water splitting. This study aims to determine the characterization of iron-based nanomaterials (iron sulfide - iron hydroxide) as a water splitting catalyst in general. Iron sulfide synthesis was carried out using hydrothermal sulfidation method for 6 hours at 80 oC with nickel foam as substrate. Synthesis of iron sulfide varying the concentration of sodium sulfide nonahydrate (0.0125 M, 0.025 M, 0.05 M and 0.1 M) produced brownish yellow to blackish grey colored samples. Characterization results using XRD showed that iron sulfide peaks were detected at higher concentrations of sodium sulfide nonahydrate. Based on the results of analyzing iron hydroxide using SEM, it is known that the sample is in the form of nano walls and on iron sulfide, it is known that the sample is in the form of nanoscale particles. Based on electrochemical measurement results, iron hydroxide can be a good catalyst for hydrogen evolution reaction (HER) compared with commercial Pt/C. The overpotential of iron hydroxide is smaller than Pt/C, which is only 15 mV at a current density 10 mA/cm2 and iron sulfide can be a good catalyst for oxygen evolution reaction (OER) with electrocatalytic measurement results close to commercial RuO2. This is indicated by the small overpotential (260 mV at current densisty 10 mA/cm2 and small tafel slope (51 mV/dec).