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Silver-and-Sulphur-Codoped Fe3O4/TiO2 as a Magnetically Separable Photocatalyst for Methylene Blue Degradation under Visible Light Kunarti, Eko Sri; Agustiningsih, Dewi; Pambudi, Fajar Inggit; Rusli, Stefen; Rusdiarso, Bambang
Molekul Vol 19 No 1 (2024)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.jm.2024.19.1.9508

Abstract

This research aimed to investigate how the addition of silver and sulphur dopants modified the TiO2 photocatalyst to enhance its responsiveness to visible light and improve its photocatalytic activity for methylene blue degradation. In addition, Fe3O4 was also added as a core to add magnetic properties to the photocatalyst material. The Fe3O4/TiO2-Ag/S materials were prepared using FeCl3.6H2O and FeSO4.7H2O as the magnetite precursors, titanium tetraisopropoxide (TTIP) as the TiO2 precursor, while AgNO3 and CH4N2S were used as the sources for silver and sulphur dopants, respectively. The synthesized materials were next characterized using FT-IR, XRD, UV-Vis spectrophotometer, SEM-EDX, TEM, and VSM. The activity of the photocatalyst was then assessed through methylene blue degradation in a closed reactor involving various contained Ag:S ratios and reusability examination. The evaluation of photocatalytic degradation results was performed using UV-Vis spectrophotometry. Afterwards, the research findings indicate that the Fe3O4/TiO2-Ag/S was successfully synthesized and exhibited magnetic properties with a saturation magnetization value of 5.33 emu/g. The highest photocatalytic activity (98.21%) was observed in Fe3O4/TiO2-Ag/S (1:1) with a band gap energy value of 2.64 eV under visible light exposure at pH 10, 120 min, 10 mg mass of the photocatalyst, and methylene blue concentration of 5 mgL-1. Furthermore, the Fe3O4/TiO2-Ag/S photocatalyst was known to perform good stability through four reuse cycles.
Investigating the Structure of Defects in Heterometallic Zeolitic Imidazolate Frameworks ZIF-8(Zn/Cd) and Its Interaction with CO2 Using First-Principle Calculations Pambudi, Fajar Inggit; Sutarno, Sutarno; Hatmanto, Adhi Dwi; Patmawati, Mita; Utari, Tika Dwi
Bulletin of Chemical Reaction Engineering & Catalysis 2024: BCREC Volume 19 Issue 2 Year 2024 (August 2024)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20136

Abstract

Inducing defect in metal-organic frameworks (MOFs) is one of the strategies to modify the structure and properties of this functional material. Defect may occur in a pristine MOF due to missing organic linkers, metal centres and/or other structural behaviours. In this study, the structure of defects in multicomponent MOFs especially heterometallic MOFs of zeolitic imidazolate framework (ZIF-8(Zn/Cd)) was examined to unveil the possible preference defect formation due to missing 2-methylimidazolate (MeIm) and metal centres of Cd2+ and Zn2+. Assuming defect formation due to the reaction between ZIF-8(Zn/Cd) and water, MeIm linker removal is energetically lower than removing metal centres of either Cd2+ or Zn2+. But, the MeIm linker is easier to be removed when it is connected to Cd2+ (Cd-MeIm-Cd) than when it is connected to Zn2+ (Zn-MeIm-Zn). Defect in ZIF-8(Zn/Cd) affects the band gap energy to give slightly lower value than it in pristine ZIF-8(Zn/Cd). Non-covalent interaction (NCI) and interaction region indicator (IRI) analyses were also performed to indicate possible intermolecular forces such as van der Waals and attractive forces present in non-defective and defective ZIF-8(Zn/Cd). The presence of defects in mixed-metal ZIF-8(Zn/Cd) was also tested for its potential use on CO2 adsorption. The interaction energy of CO2 inside defective ZIF-8(Zn/Cd) indicates an exothermic behaviour where CO2 molecule has a preference to be adsorbed inside the framework. This is especially when the capping agents at the defective ZIF-8(Zn/Cd) sites are removed to give open metal sites. This study provides insight how defects in multicomponent MOFs might presence affecting the structural and properties changes. Copyright © 2024 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). 
Immobilization of Ni(II) on Amine-Functionalized Mesoporous Silica as Catalyst for Benzyl Alcohol Acetylation Reaction Nabilah, Wardah; Kunarti, Eko Sri; Pambudi, Fajar Inggit
Makara Journal of Science
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

In this study, amine-functionalized and Ni(II)-immobilized mesoporous silica materials were synthesized. This research aimed to synthesize mesoporous silica based on rice husk ash functionalized with amine and immobilized with Ni(II). The activity of amine-functionalized and Ni(II)-immobilized mesoporous silica materials was studied for the acetylation of benzyl alcohol with acetic anhydride as the acetylating agent. First, mesoporous silica was synthesized using rice husk ash using the sol–gel method, followed by amine functionalization using (3-aminopropyl)triethoxysilane (APTES) and Ni(II) immobilization through ultrasonic treatment. The results obtained showed that amine-functionalized and Ni(II)-immobilized mesoporous silica (SiO2/APTES/Ni(II)) were successfully synthesized, confirmed by Fourier transform infrared and Energy-dispersive X-ray spectrometry data. In addition, the synthesized materials had an average pore diameter of 12.83 nm. Afterward, the catalytic activity test showed that SiO2/APTES/Ni(II) was able to convert 98.34% of benzyl alcohol in the acetylation reaction at 45 °C for 5 h. The use of the SiO2/APTES/Ni(II) catalyst for three cycles obtained percent conversion values with a slight decreases (98.34%, 95.20%, and 90.61%).