Synthesis of Fe3O4/SiO2/TiO2 nanocomposite and its application as photocatalyst in Carboxymethyl Cellulose (CMC) photocracking had been conducted. Magnetite preparation was carried out by sono-coprecipitation method. The deposition of SiO2 and TiO2 were performed by sol-gel method under ultrasonic irradiation. All material products were characterized by X-ray diffraction (XRD), Fourier transform infra-red spectrophotometry (FT-IR), and transmission electron microscopy (TEM). The final material product was also analysed by specular reflectance UV-Visible (SR-UV-Vis). The product of photocracking was analysed by gas chromatography – mass spectrometry (GC-MS).The XRD diffractogram and FT-IR spectra confirmed the presence of Fe3O4, SiO2, and anatase phase of TiO2. The TEM image revealed the presence of nanocomposite with core-shell structure. The SR-UV-Vis spectrum was used to determine band gap energy of the photocatalyst and it gave a result of 3.22 eV. The GC chromatogram of photocracking product indicated some major fractions. The MS spectra showed that some major fractions were smaller molecules including methanol, the component of biofuel.
Abstrak: Teknik recovery emas (Au) yang berkembang bersifat berbahaya dan berdampak buruk terhadap lingkungan. Penelitian ini bertujuan untuk mensintesis adsorben ramah lingkungan termodifikasi secara kimia dengan asam sulfat dari kulit mangga. Adsorben hasil sintesis selanjutnya diaplikasikan sebagai adsorben selektif emas (Au) dalam larutan. Nilai kapasitas, konstanta laju dan energi adsorpsi ditentukan dengan uji kinetika adsorpsi. Sintesis adsorben dilakukan dengan modifikasi menggunakan H2SO4 dengan bahan dasar kulit mangga sehingga membentuk struktur taut ulang (cross-link). Produk sintesis dikarakterisasi menggunakan FTIR dan SEM sebelum maupun sesudah menyerap emas. Data kandungan emas setelah proses adsorpsi diukur dengan alat AAS. Spektra FTIR menunjukan keberhasilan sintesis adsorben kulit mangga termodifikasi asam sulfat dan interaksinya dengan emas (Au), yaitu pada bilangan gelombang 1118,71 cm -1 yang menunjukkan ikatan C-O-C linkage yang terjadi antar selulosa dan pelebaran pada 3433,29 cm -1 akibat interaksi antara gugus OH dan Au(III). Hasil SEM menunjukan perbedaan morfologi permukaan adsorben sebelum dan sesudah menyerap emas yang terjadi karena penutupan rongga adsorben akibat peristiwa adsorpsi-reduksi Au(III). Proses adsorpsi emas oleh adsorben yang disintesis mengikuti model kinetika orde dua semu (pseudo-2) dengan nilai kapasitas, konstanta laju, dan energi adsorpsi adalah 130 mmol kg -1 , 0,1137 mM -1 s -1 dan 5442,72 J mol -1 .Abstract: Gold (Au) recovery techniques that are commoly used were dangerous and have a negative impact on the environment. This study aims to synthesize eco-friendly adsorbent prepared from chemically modified with sulfuric acid from mango peel. The synthesized adsorbent was then applied as a selective absorbent for gold (Au) in solution. Capacity, rate constant and adsorption energy were determined by adsorption kinetics test. The synthetic of adsorbent was carried out by H2SO4 modification to form a cross-link structure with mango peel as a basic material. Synthesized products before and after adsorption are characterized by FTIR and SEM. Data on gold content after the adsorption process was measured by AAS. FTIR spectra showed the synthesis of sulfuric modified mango peel adsorbent at 1118,71 cm -1 that associated C-O-C linkage between cellulose was successful and its interaction with gold (Au) was showed at 3433,29 cm -1 broad band that associated the interaction of OH groups and Au(III). SEM image showed differences in the morphology of the adsorbent surface before and after adsorbing gold because the hole closed on adsorbent, it was caused by Au(III) adsorption-reduction. The adsorption process of gold by the adsorbent synthesized followed pseudo-second order kinetics (pseudo-2) with capacity values, rate constants, and adsorption energies were 130 mmol kg -1 , 0.1137 mM -1 s -1 and 5442.72 J mol -1 .
TiO2 modified Fe3O4 nanocomposite as photocatalyst in CO2 indirect reduction was synthesized by an ultrasonic-assisted sol-gel method and its photocatalytic activity was studied as well. The modification of the TiO2 composite was attempted to modify titanium dioxide to have better performance as a photocatalyst. Magnetite synthesis was carried out by the sono-coprecipitation method with the addition of the capping agent. The magnetite was coated with TiO2 via the sol-gel method under ultrasonic irradiation. The products were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectrophotometry (FT-IR), transmission electron microscopy (TEM), and turbidimetry. The final product was also analyzed by diffuse reflectance UV-Visible (DR-UV) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX). The product of indirect reduction was analyzed by gas chromatography-mass spectrometry (GC-MS). Photocatalytic reaction with Fe3O4/TiO2 nanocomposite produced a higher concentration of methanol than using TiO2. Methanol concentration produced from the photocatalytic reaction using TiO2 and Fe3O4/TiO2 was 6.63% and 16.82%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.