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Journal : Science and Technology Indonesia

Preparation of Hydrochar from Salacca zalacca Peels by Hydrothermal Carbonization: Study of Adsorption on Congo Red Dyes and Regeneration Ability Mauizatul Hasanah; Alfan Wijaya; Fitri Suryani Arsyad; Risfidian Mohadi; Aldes Lesbani
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3498.283 KB) | DOI: 10.26554/sti.2022.7.3.372-378

Abstract

Hydrochar of Salacca zalacca peels (HC-SP) is prepared by hydrothermal carbonization treatment of Salacca zalacca peels (SP) obtained from local fruits at Palembang, South Sumatera, Indonesia, with the resulting yield weight reaching 90%. Materials are characterized using the XRD diffraction, FTIR spectrum, and SEM-EDX. The XRD pattern shows the characteristics of the formation of amorphous compounds. The FTIR spectrum confirms the presence of functional groups O-H, C-H, C=C, and C-O. Data of SEM-EDX show that materials have heterogeneous morphologies, form aggregates, and in HC-SP materials there is an increase in carbon content from the initial material. The capacity of SP in the congo red (CR) adsorption process is 33.003 mg/g and increases to 133.333 mg/g in HC-SP. The maximum dye adsorbed was achieved at pH 4. The adsorption kinetics followed PSO with the equilibrium adsorption occurring at 90 minutes, and the adsorption isotherm followed the Langmuir isotherm with the value of R2 closer to the value of 1. A positive 4H value indicated that the adsorption is an endothermic process. In contrast, an 4S value suggested that the degree of irregularity in the adsorption process is small in large concentrations. Based on data regeneration ability, materials of SP and HC-SP can be used in the three cycles regeneration process of the CR adsorption process. The adsorption process of CR occurs physically and chemically based on enthalpy values and FT-IR data after being adsorbed with CR.
Catalytic Oxidative Desulfurization of Dibenzothiophene by Composites Based Ni/Al-Oxide Nur Ahmad; Alfan Wijaya; Amri; Erni Salasia Fitri; Fitri Suryani Arsyad; Risfidian Mohadi; Aldes Lesbani
Science and Technology Indonesia Vol. 7 No. 3 (2022): July
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1788.962 KB) | DOI: 10.26554/sti.2022.7.3.385-391

Abstract

In the present study, composite layer double hydroxide-metal oxide (Ni/Al-TiO2 and Ni/Al-ZnO) was successfully prepared and used as catalyst of oxidative desulfurization of dibenzothiophene. Characterization of catalyst was used XRD, FTIR, and SEM-EDS. The structure of Ni/Al-LDH, TiO2, and ZnO in composite Ni/Al-TiO2 and Ni/Al-ZnO was consistent, which also indicated that the preparation of composite did not change the form of precursors. FTIR spectra of Ni/Al-TiO2 and Ni/Al-ZnO absorption band at 3398, 1639, 1339, 832, 731, and 682 cm−1. The catalysts have an irregular structure, TiO2 and ZnO adhere to the surface of Ni/Al LDH. The percent mass of Ti and Zn on the composite at 29.3% and 18.2%, respectively. The acidity of Ni/Al LDH increased after being composited with TiO2 and ZnO. The optimum reaction time, dosage catalyst, and temperature were 30 min, 0.25 g, and 50°C, respectively, and n-hexane as a solvent. The percentage conversion of dibenzothiophene on Ni/Al-LDH, TiO2, ZnO, Ni/Al-TiO2, and Ni/Al-ZnO were 99.44%, 91.92%, 95.36%, 99.88%, and 99.90%, respectively. The catalysts are heterogeneous system and the advantage is that can be used for reusability. After 3 times catalytic reactions, the conversion of dibenzothiophene still retains more than 80%, even Ni/Al-TiO2 and Ni/Al-ZnO composites still 97.79% and 98.99%, respectively.
Review of The Effectiveness of Plant Media Extracts in Barium Hexaferrite Magnets (BaFe12O19) Jaya Edianta; Nanang Fauzi; Marzuki Naibaho; Fitri Suryani Arsyad; Idha Royani
Science and Technology Indonesia Vol. 6 No. 2 (2021): April 2021
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.2021.6.2.39-52

Abstract

Betel leaf is a typical Indonesian herbal plant that propagates on other tree trunks. So far, betel leaf has only been used in biomedicine and traditional medicine, whereas the chemical compounds of betel leaf can be used to absorb electromagnetic waves. In this mini-review, we review several research results to discuss the potential effectiveness of betel leaf in barium hexaferrite as an absorber of electromagnetic radiation. We compiled this mini-review based on the literature review method that is discussed extensively and in-depth regarding the chemical composition of betel leaf, modification of the development of barium hexaferrite material with betel leaf media extract, characteristics of BaFe12O19 as absorption of electromagnetic waves, and the effectiveness of media extracts in BaFe12O19 as absorption of electromagnetic waves. Based on the results of the literature review, the modification of BaFe12O19 material synthesis can include microemulsion, solid-state, coprecipitation, sol-gel, and hydrothermal synthesis. So far, hydrothermal synthesis is a synthesis method of mixing betel leaf extract media and ferrite-based magnets that have been studied before. Betel leaf in ferrite-based magnetic materials has been studied not to damage the surface morphology and characteristics of the magnetic material. The results of the assessment also show the effectiveness of adding other elements or compounds such as Ni, Al2O3, and composites in ferrite-based magnetic materials that can absorb more than 90% of electromagnetic waves in the frequency range 2-18 GHz.
The Characteristic Analysis of Caffeine Molecularly Imprinted Polymers Synthesized Using The Cooling-Heating Method, for Application as a Sensor Material Idha Royani; Amalia Amalia; Jorena Jorena; Fitri Suryani Arsyad; Erry Koriyanti; Fiber Monado
Science and Technology Indonesia Vol. 6 No. 4 (2021): October
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.2021.6.4.256-260

Abstract

The cooling-heating method was used to successfully synthesize molecularly imprinted polymers on caffeine. Caffeine was used as a template and mixed with chloroform solvent, methacrylic acid as a monomer, ethylene glycol dimethacrylate as a cross-linker, and benzoyl peroxide as an initiator. The solution was stirred for 15 minutes and placed in a vial. Then it was placed in a cooler with a temperature of -5○C for 60 minutes and then inserted into an oven with an increasing temperature at 75○C, 80○C, and 85○C for 3, 2 and 1 hour, respectively. Furthermore, the repeated washing process resulted in solid polymer, which was subjected to template leaching to produce polymers with specific cavities called molecularly imprinted polymers (MIP). The resulting caffeine polymer and MIP were tested using SEM, FTIR, and XRD methods. In addition, the SEM image analysis data showed 388 cavities in the polymer after template leaching, compared to the 121 cavities in the unwashed polymer. This result was supported by the FTIR spectrum analysis which showed that caffeine MIP has a higher transmittance value than the polymer. Therefore, the caffeine concentration was significantly reduced after the leaching process. The XRD spectra showed that caffeine MIP had a smaller halfmaximum diffraction peak width (FWHM) compared to the polymer. Also, the low FWHM value depicted a larger crystalline size in the caffeine MIP compared to the polymer.