Sintesis Komposit Fe3o4-sio2-tio2 dan Aplikasinya untuk Mendegradasi Limbah Zat Warna Methylene Blue

SINTESIS KOMPOSIT Fe3O4-SiO2-TiO2 DAN APLIKASINYA UNTUK MENDEGRADASI LIMBAH ZAT WARNA METHYLENE BLUE. Telah dilakukan sintesis komposit nanopartikel Fe3O4-SiO2-TiO2dengan metoda presipitasi. Bahan komposit nanopartikel Fe3O4-SiO2-TiO2 dapat digunakan sebagai bahan untuk mendegradasi polutan organik yang larut di dalam air. Hasil pengukuran sampel dengan difraktometer sinar-X (XRD) menunjukkan adanya struktur Fe3O4 magnetit dan TiO2 anatase, sedangkan data EDS menunjukkan bahwa komposit mengandung atom Fe, Ti, Si dan O. Dapat disimpulkan bahwa komposit terdiri dari fasa Fe3O4, SiO2 amorf dan fasa TiO2. Pengamatan sampel dengan TEM terhadap komposit Fe3O4-SiO2-TiO2 belum secara jelas menunjukkan bahwa komposit Fe3O4-SiO2-TiO2 membentuk struktur coreshell meskipun nano partikel Fe3O4 sebagai inti diselimuti oleh lapisan SiO2 dan TiO2. Komposit Fe3O4- SiO2-TiO2memiliki nilai magnetisasi saturasi sekitar 20 emu/gram jauh lebih kecil bila dibandingkan bahan penyusunnya Fe3O4 yang mencapai sekitar 69 emu/gram. Namun demikian bahan tersebut masih mudah dipisahkan dari pelarutnya menggunakan magnet permanen. Kondisi optimum adsorbsi dan degradasiMB oleh komposit Fe3O4-SiO2-TiO2dicapai pada pH 9. Komposit nanopartikel Fe3O4-SiO2-TiO2mampumengadsorpsi dan mendegradasi polutan organik MB sebanyak 98% dalam lingkungan alkalin

Characterization of High Coercivity Strontium Hexaferrite by Coprecipitation

The Strontium hexaferrite (SrO.6Fe2O3) has been successfully synthesized by coprecipitationmethod in an aqueous solution of Sr(NO3)2.6H2O, Fe(NO3)3.9H2O and Tetramethylammonium Hydroxide (TMAOH). The resulted precursors were then calcinated at temperature of 800 °C to 1000 °C for 2 hours. The results revealed that the single phase of strontium hexaferrite was formed at low annealing temperature of 800 °C for 2 hours with magnetic coercivity of 6 kOe, and tends to decrease with increasing annealing temperature. The saturation magnetization determined from analyzed magnetic hysteresis curve by using Jiles-Atherton (JA) method, were obtained from 66-41 emu/g depend on the annealing temperatures. The magnetic properties of synthesized strontium hexaferrite obtained in this activities were improved compared to the commercial one which coercivity of 1.7 kOe

PENGARUH LARUTAN PENGENDAP TERHADAP PEMBENTUKAN HEKSAFERIT BaO.6 Fe2O3

PENGARUH LARUTAN PENGENDAP TERHADAP PEMBENTUKAN HEKSAFERIT BaO.6 Fe2O3. Nano-partikel BaO.6 Fe2O3 heksaferit telah berhasil disinteis dengan metoda kimia basah menggunakan larutan pengendap natrium hidroksida (NaOH) dan tetramethyl ammonium hidroxida (TMOH). Metoda kimia basah yang digunakan dalam penelitian ini adalah metoda ko-presipitasi. Identifikasi fasa sampel dilakukan menggunakan teknik difraksi sinar-X dan mikrostruktur sampel diamati dengan Transmission Electron Microscope (TEM) sedangkan perubahan sifat kemagnetan bahan diukur menggunakan Vibrating Sample Magnetometer (VSM). Hasil pengamatan menunjukkan bahwa koersivitas intrinsik (Hci) dan remanensi magnet (σr) BaO.6 Fe2O3 hasil sintesis menggunaka larutan TMOH diperoleh sekitar 5,1 kOe dan 31,3 emu/gr, lebih tinggi bila dibandingkan dengan koersivitas dan magnet permanen BaO.6 Fe2O3 hasil sintesis dengan larutan NaOH dengan Hci = 4,56 kOe dan σr = 27,2 emu/gr. Nilai koersivitas yang tinggi disebabkan oleh karena ukuran partikel BaO.6 Fe2O3 hasil sintesis menggunakan larutan TMOH sangat halus. Semakin tinggi suhu sintering, koersivitas magnet cenderung turun yang disebabkan oleh pertumbuhan partikel

KARAKTERISASI STRONSIUM HEKSAFERIT KOERSIVITAS TINGGI HASIL SINTESIS DENGAN METODE KOPRESIPITASI

KARAKTERISASI STRONSIUM HEKSAFERIT KOERSIVITAS TINGGI HASIL SINTESIS DENGAN METODE KOPRESIPITASI. Stronsium heksaferit (SrO 6 Fe2O3) telah berhasil disintesis menggunakan metode kopresipitasi dari larutan Sr(NO3)2 6 H2O, Fe(NO3)3 9 H2O dan Tetramethyl ammonium Hidroksida (TMAOH). Prekursor yang diperoleh kemudian dikalsinasi pada suhu 800 oC hingga 1000 oC selama 2 jam. Fasa tunggal stronsium heksaferit telah terbentuk pada kalsinasi suhu 800 oC dengan koersivitas magnet 6 kOe dan cenderung menurun dengan peningkatan suhu annealing. Saturasi magnet ditentukan dari analisis kurva histeresis magnet menggunakan metode Jiles-Atherton (JA), berkisar dari 66 emu/g hingga 41 emu/g bergantung pada suhu annealing. Sifat magnet stronsium heksaferit hasil sintesis jauh lebih baik bila dibandingkan dengan produk komersial dengan koersivitas magnet yang hanya 1,7 kOe

Preparation of Magnetic-ZnO Nanocomposite by High Energy Milling Method for Methyl Orange Degradation

A magnetic Fe3O4/ZnO nanocomposite (NCs) was prepared by a high energy milling (HEM) method. In the present study, the ZnO catalyst was prepared through two ways. The ZnO was synthesized by coprecipitation method (ZnO (S)), and ZnO directly used a commercial product (ZnO (Ald)). The prepared NCs were characterized using X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared (FTIR), transmission electron microscope (TEM), and UV-Vis spectrophotometer. The XRD refinement indicates that Fe3O4 nanoparticle (NP) is a single phase and well indexed to cubic spinal structured magnetite. The Fe3O4/ZnO (S) and Fe3O4/ZnO (Ald) NCs are consisted of Fe3O4 and ZnO phases. The VSM result show that Fe3O4 NP, Fe3O4/ZnO (S), and Fe3O4/ZnO (Ald) NCs possess super-paramagnetic properties with saturation magnetization (Ms) is 102 emu.g-1, 28 emu.g-1 and 26 emu. g-1, respectively. The TEM observation shows that the average diameter of Fe3O4 is approximately 15 nm, while the thickness both of ZnO shell is ranging 20 nm - 50 nm. The average diameter of TiO2 P25 particle as catalyst was observed about 20 nm. The photocatalytic activity of catalysts were evaluated based on the degradation of methyl orange (MO) dye solution. The result shows that at pH = 7, the Fe3O4/ZnO (Ald) NC can degrade the pollutant in MO dye solution to 99 %, where as at pH = 3, the catalyst TiO2 P25 degrade only 96%

Synthesis of Mfe12o19 (M=ba,sr) Hexaferrite Nano-particle Using Co-precipitation Method

Synthesis of MFe12O19 (M=Ba,Sr) hexaferrite nano-particle using co-precipitation method has been done. Base materials used has a high purity according to Merck catalog of Ba(NO3)2.6H2O, Sr(NO3).6H2O, dan Fe(NO3)3.9H2O powders. In co-precipitation method Ba(II), Sr(II) and Fe(II) hydroxide precursors were precipitated during the reaction between the aqueous solution of metal nitrates and 1-M aqueous solution of natrium hydroxide, which served as a precipitating reagent. The precipitation was performed at 45 °C and pH value of 12.6 respectively. Sintering process of the precursor was done at the various temperature of 900 and 1000°C for 5 hours respectively. Phase identification was measured bymeans of x-rays diffraction. The magnetic properties change before and after sintering process was measured by vibrating sample magnetometer. The microstructure of the powder sample was observed by scanning electron microscope. Under the order of x-rays diffraction patterns could be reveal that both of the samples have established the crystal system of BaFe12O19 and SrFe12O19 hexaferrite characterized by the presence of a sharp intensity peak. Impact of the sintering process to the phase system of BaFe12O19 and SrFe12O19 is clearly visible on changing of the magnetic properties, namely intrinsic magnetic coercivity and magnetic remanence which is increased sharply after sintering process. Increase in both parameters indicates that the precursor has undergone a process of crystallization into the BaFe12O19 and SrFe12O19 hexaferrite phase system. Magnetic remanence and intrinsic coercivity of BaFe12O19 successively obtained about 30.3emu/g and 4.7kOe higher than the magnetic remanence and intrinsic coercivity of SrFe12O19 that only 22.9emu/g and 3.5kOe. This increasing the value of the intrinsic magnetic coercivity is closely related to the size of the BaFe12O19 crystallites more subtle

Preparation of Magnetic-ZnO Nanocomposite by High Energy Milling Method for Methyl Orange Degradation

A magnetic Fe3O4/ZnO nanocomposite (NCs) was prepared by a high energy milling (HEM) method. In the present study, the ZnO catalyst was prepared through two ways. The ZnO was synthesized by coprecipitation method (ZnO (S)), and ZnO directly used a commercial product (ZnO (Ald)). The prepared NCs were characterized using X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared (FTIR), transmission electron microscope (TEM), and UV-Vis spectrophotometer. The XRD refinement indicates that Fe3O4 nanoparticle (NP) is a single phase and well indexed to cubic spinal structured magnetite. The Fe3O4/ZnO (S) and Fe3O4/ZnO (Ald) NCs are consisted of Fe3O4 and ZnO phases. The VSM result show that Fe3O4 NP, Fe3O4/ZnO (S), and Fe3O4/ZnO (Ald) NCs possess super-paramagnetic properties with saturation magnetization (Ms) is 102 emu.g-1, 28 emu.g-1 and 26 emu. g-1, respectively. The TEM observation shows that the average diameter of Fe3O4 is approximately 15 nm, while the thickness both of ZnO shell is ranging 20 nm - 50 nm. The average diameter of TiO2 P25 particle as catalyst was observed about 20 nm. The photocatalytic activity of catalysts were evaluated based on the degradation of methyl orange (MO) dye solution. The result shows that at pH = 7, the Fe3O4/ZnO (Ald) NC can degrade the pollutant in MO dye solution to 99 %, where as at pH = 3, the catalyst TiO2 P25 degrade only 96%.

Sintesis dan Karakterisasi Komposit Fe 3 O 4 @Zno dengan Metoda Presipitas

SYNTHESIS AND CHARACTERIZATION OF Fe3O4@ZnO COMPOSITE THROUGHPRECIPITATION METHOD. Fe3O4@ZnO composite has been synthesized trough precipitationmethod with the ratio between Fe3O4 and ZnO are 1:1, 1:2, dan 1:3. Characterization of the samplewas performed using X-ray diffractometer (XRD), scanning electron microscope (SEM) equipped withenergy dispersive spectrophotometer (EDS), vibrating sample magnetometer (VSM) andtransmission electron microscope (TEM). The XRD pattern shows that the sample consisted of Fe3O4 nanoparticles and ZnO phases. Magnetic saturation value (Ms) of Fe3O4were measured by VSMobtained about 62.92 emu / g, but then the value of Ms dropped to13.60 emu/g with the addition ofZnO content. TEM observation showed a spherical structure of Fe3O4 aggregate about 20 nm Indiameter, and embedded in the ZnO shell. EDS spectrum revealed that the Fe3O4@ZnO compositeswere only observed three types of elements, namely Fe, Zn and O. This shows evidence that thecoating on the surface of Fe3O4nanoparticles is the outer shell of ZnO. Fe3O4@ZnO composites withFe3O4and ZnO ratio is 1: 2 shows a more homogeneous coating ZnO

PENGARUH SUHU DAN WAKTU SINTER TERHADAP PENUMBUHAN FASA SUPERKONDUKTOR GdBa2Cu3O7-x

PENGARUH SUHU DAN WAKTU SINTER TERHADAP PENUMBUHAN FASA SUPERKONDUKTOR GdBa2Cu3O7-x. Superkonduktor merupakan bahan yang mempunyai nilai resistansi nol pada suhu kritis dan dapat disintesis melalui berbagai metode. Bahan ini digunakan untuk berbagai device piranti elektronik. Pada penelitian ini GdBa2Cu3O7-x disintesis dari garam nitrat Gd, Ba dan Cu di dalamgaram cair urea. Campuran tersebut dipanaskan dan diaduk pada suhu 120 oC selama 16 jam, kemudian dipanaskan hingga kering.Hasil ini digerus dan disinter dengan suhu bervariasi 800 oC hingga -950 oC dan masing-masing divariasi selama 1 jamhingga 20 jam.Hasil dianalisis dengan SEM, EDS, difraktometer sinar-X dan uji efekMeissner.Analisis menunjukkan bahwa fasa GdBa2Cu3O7-x terbentuk semakin sempurna mulai sinter pada suhu 925 oC selama 20 jam. Kondisi optimum sinter 950 oC 5 jam