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All Journal POSITRON Communications in Science and Technology
Rati, Yolanda
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Energy Engineering Physics

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Biosynthesis of Zinc Oxide Powder Using Sandoricum koetjape Peel Extract at Various Annealing Temperature Rini, Ari Sulistyo; Hidayanti, Nurul; Rati, Yolanda
POSITRON Vol 11, No 2 (2021): Vol. 11 No. 2 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (487.835 KB) | DOI: 10.26418/positron.v11i2.49699

Abstract

Zinc oxide (ZnO) synthesized with natural reductants has attracted the attention of researchers because it is environmentally friendly and non-toxic. In this study, ZnO was prepared using Sandoricum koetjape (S. koetjape) peel extract. An aqueous extract of S. koetjape peel was used as biological reduction agent for the synthesis of ZnO from zinc nitrate hexahydrate. The ZnO powder obtained was annealed at different temperatures i.e, 300°C, 400°C, and 500°C for 1 hour. Structural, morphological, optical properties, and functional groups of samples were analyzed using X-Ray Diffraction, Scanning Electron Microscopy, UV-Vis Spectroscopy, and Fourier Transform Infrared Spectroscopy, respectively. The X-ray diffraction pattern shows that pure hexagonal wurtzite structure of ZnO particles can be achieved after annealing. The crystal size has also increased with increasing annealing temperature. SEM photo demonstrates the transformation of ZnO particle from spherical to microflower due to annealing. The widest absorption peaks in the UV-Vis spectrum was occurred after annealing at 500°C. The bandgap energy of ZnO increases after annealing from 3.08 eV to 3.20 eV. The FT-IR analysis confirms O-H functional group from extract has been decomposed due to the annealing process. Based on this study, biosynthesized ZnO using Sandoricum koetjape peel extract requires annealing process to improve the purity, enhance the light absorbance and change the microstructure of ZnO.
Microwave-assisted biosynthesis and characterization of ZnO film for photocatalytic application in methylene blue degradation Sulistyo Rini, Ari; Nabilla, Averin; Rati, Yolanda
Communications in Science and Technology Vol 6 No 2 (2021)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.6.2.2021.484

Abstract

This study aims to investigate the physical characteristics and photocatalyst activity of biosynthesized ZnO with pineapple (Ananas comosus) peel extract under microwave irradiation. The ZnO powder was prepared in two different concentrations of zinc nitrate hexahydrate (ZNH) at 200mM (Z-200) and 500 mM (Z-500). The optical, structural, and morphological properties of ZnO were analyzed using UV-Vis spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM), respectively. The UV-Vis absorption spectrum showed a wide absorbance peak of ZnO at the wavelength of 300-360 nm with a bandgap energy of 3.22 and 3.25 eV. The XRD result confirmed the wurtzite structure of ZnO with high crystallinity. SEM morphology showed spherical particles with an average particle size of 190-220 nm. For photocatalytic application, ZnO film was fabricated via the doctor blade method from microwave-assisted biosynthesized ZnO powder. ZnO films were then applied under UV-irradiation to examine the photocatalytic degradation of methylene blue. It was found that the catalytic behavior of ZnO film was affected by the starting ZNH concentration with maximum effectiveness of 46% degradation after 2 h.
Microwave-assisted biosynthesis of flower-shaped ZnO for photocatalyst in 4-nitrophenol degradation Sulistyo Rini, Ari; Aji, Arie Purnomo; Rati, Yolanda
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.937

Abstract

In this paper, the flower-shaped ZnO particles have been prepared via microwave-assisted biosynthesis technique using an aqueous extract of Sandoricum koetjape peel at various irradiation powers, i.e. 180, 360, 540, and 720 Watt. The synthesized flower-shaped ZnO particles were characterized using UV-Vis spectroscopy, x-ray diffraction (XRD), and field emission scanning electron microscope (FESEM). The UV-vis spectra exhibited ZnO absorption peaks in the UV region with band gap energy in the range of 3.25 - 3.29 eV. XRD analysis confirmed the hexagonal wurtzite crystal with the high purity of ZnO particles. The flower-shaped morphology of ZnO was evident in FESEM images with the decrease of particle diameter as the radiation power increased from 257 to 447 nm. ZnO prepared at 720 Watt (Z-720) succeeded in degrading 4-nitrophenol with the highest efficiency of 84.8 % after 240 min. Consequently, biosynthesis ZnO will have a great opportunity to be applied in degrading wastewater pollutants.
Utilizing Pometia Pinnata leaf extract in microwave synthesis of ZnO nanoparticles: Investigation into photocatalytic properties Sulistyo Rini, Ari; Rati, Yolanda; Maheta, Gema; Aji, Arie Purnomo; Saktioto
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1407

Abstract

In this work, ZnO photocatalyst has been synthesized using matoa (Pometia pinnata) leaf extract under various microwave irradiation powers at 360, 540, and 720 Watts for 3 minutes on each. The UV-Vis absorption spectra of ZnO exhibited a peak in the ultraviolet region 300-360 nm. UV-Vis absorption analysis revealed a decrease in the band gap energy from 3.15 eV to 3.10 eV as the irradiation power increased. Field emission scanning electron microscopy (FESEM) images displayed spherical and nanoplatelet morphology with a decrease in particle size observed from 773 to 709 nm with increasing irradiation power. X-ray diffraction (XRD) analysis confirmed the hexagonal wurtzite structure of ZnO with crystallite sizes in the range of ~18-20 nm. The synthesized ZnO nanoparticles was successfully employed as a photocatalyst in 4-nitrophenol degradation, achieving the highest degradation percentage of 82.7% at 540 Watts with a corresponding reaction rate constant of 0.0126/min. In conclusion, the microwave-assisted synthesis of ZnO using on matoa leaf extract demonstrated significant potential for the degradation of organic pollutants, thereby contributing to water purification efforts.
Co-Authors Aji, Arie Purnomo Hidayanti, Nurul Maheta, Gema Nabilla, Averin Rini, Ari Sulistyo Saktioto Sulistyo Rini, Ari