ANALISA GUGUS FUNGSI PADA NANOPARTIKEL MAGNESIUM FERRITE (MgFe2O4) YANG DIENKAPSULASI DENGAN POLYETHYLENE GLYCOL (PEG-4000) DAN SILIKA

Magnesium Ferrite Magnesium (MgFe2O4) magnetic nanoparticles have been successfully carried out by varying the concentrations of PEG-4000 and silica as encapsulation materials using coprecipitation methods. The X-ray Diffraction (XRD) analysis showed that new phases appeared in MgFe2O4 after PEG-4000 encapsulation, ie α-Fe2O3 having a paramagnetic rhombohedral and γ-FeO (OH) structure. The particle size of MgFe2O4 before encapsulation was 10.5 nm, after encapsulation with PEG-4000 became 5.2 nm and encapsulation with silica became 18.8 nm. In encapsulation with silica, the peak of the new diffraction field 222 which is a crystal appears. The result of Fourier Transform Infra-Red (FTIR) analysis showed that in MgFe2O4 coated with PEG-4000, there was a shifting in the wave number 2885.5 cm-1 to 2924.1 cm-1 in CH bond which was the bond of PEG- 4000 and a shifting in the wave number 316.3 cm-1 to 300.9 cm-1 on the metal oxide bond (MO) which is a uniform pattern of MgFe2O4. The presence of silica which has coated the magnetic material is shown in the 455.2 cm-1 number of Si-O-Si (bending) group

Effect of Red Dragon Fruit Extract as Dye in Solar Cells

Along with the development of nanotechnology, the development of solar cells entered a significant stage with the emergence of the newest generation, namely DSSC (Dye Sensitized Solar Cell). The utilization of dragon fruit skin which has been extracted as dye in dye sensitized solar cells and solar cell development to realize sustainable energy supply is the main target in this study. The method carried out begins with the synthesis of nanoparticles from organic material (TiO2), to obtain good TiO2 material as an anti-reflection, where anti-reflection is selected on DSSC technology to reduce light reflection in the visible light region. The crystal size of TiO2 was analyzed as an oxide layer material in DSSC. DSSC synthesis was carried out and the parameters of organic solar cell devices (DSSC) were optimized to obtain solar cells with good conversion efficiency. The results showed that the size of TiO2 obtained was an average of 0.211 nm and the maximum wavelength value of the extract of the dragon fruit dye solution was 530 nm. Keywords: dye, solar cell, DSSC, TiO2

Characteristics And Mineral Content of Lampung Tengah Ironsands

Characteristics and Mineral Content of Lampung Tengah Ironsands. This study is carried out to investigate the characteristics and mineral content of ironsands from Bekri, Lampung Tengah Regency by using precipitation method. The research was conducted in Physics Laboratory of Institut Teknologi Sumatera from June to September 2018. Mineral content of sand is analayzed with X-Ray Diffractometer. The extraction was varied in temperature and stirring time. The temperature is varied in 80oC, 120oC, dan 160oC and yields different size; 33.76 nm, 11.84 nm and 11.14 nm. Meanwhile, the extraction is varied for 2 hours, 4 hours and 6 hours stirring and yields particle with 43.12 nm, 11.14 nm and 11.32 size. Mineral content of ironsands in Lampung Tengah are dominated by Ilmenite and Potassium Chloride

KARAKTERISASI DAN SIFAT KEMAGNETAN PASIR BESI di WILAYAH LAMPUNG TENGAH

Karakterisasi dan pengujian sifat kemagnetan pasir besi ekstraksi di Wilayah Lampung Tengah telah dilakukan. Penelitian ini bertujuan untuk mengetahui kandungan mineral dan sifat kemagnetan dari pasir besi di daerah Bekri Kabupaten Lampung Tengah dengan menggunakan metode presipitasi basa. Penelitian ini dilakukan di Laboratorium Fisika, Institut Teknologi Sumatera pada bulan Juni hingga September 2018. Kandungan mineral pasir dianalisis menggunakan X-Ray Diffractometer (XRD). Hasil analisis ekstraksi pasir besi dengan variasi suhu 80oC, 120oC, dan 160oC berturut-turut berukuran 33.76 nm, 11.84 nm dan 11.14 nm. Sedangkan hasil analisis ekstraksi pasir besi dengan lama pengadukan yaitu 2 jam, 4 jam, dan 6 jam  berturut-turut memiliki ukuran partikel 43.12 nm, 11.14 nm, dan 11.32 nm. Hasil analisis kandungan mineral pasir besi di wilayah Lampung Tengah didominasi oleh Ilmenite dan Potassium Chloride. Kurva histerisis Vibrating Sample Magnetometer (VSM) menunjukkan bahwa pasir besi ekstraksi dari Lampung Tengah merupakan material antiferomagnetik dengan nilai magnetisasi saturasi maksimum (Ms) sebesar 5.78 memu (mili emu), magnetisasi remanen (Mr) 1.13 memu dan nilai medan koersivitas sebesar 851.68 Oe

PEMBUATAN BIODIESEL BERBAHAN BAKU FRAKSI MINYAK CPO (CRUDE PALM OIL) PARIT TERKATALISIS ZEOLIT ALAM LAMPUNG

Telah dilakukan sintesis biodiesel dari CPO parit yaitu fraksi minyak pada limbah cair pabrik CPO. Sintesis dilakukan 2 tahap, yaitu esterifikasi untuk mengkonversi asam lemak bebas menjadi metil ester dan dilanjutkan dengan transesterifikasi untuk mengkonversi trigliserida menjadi metil ester. Katalis yang digunakan berbasis Zeolit Alam Lampung (ZAL) yang dimodifikasi dengan H2SO4 0,5 M (H-ZAL) dan digunakan sebagai katalis dalam tahap esterifikasi. Katalis berikutnya yaitu ZAL yang dimodifikasi dengan KOH (OH-ZAL) dan diuji aktivitas katalitiknya dalam reaksi transesterifikasi. Konsentrasi KOH divariasikan untuk mengetahui pengaruh konsentrasi basa terhadap yield biodiesel. Hasil karakterisasi XRD menujukkan ZAL merupakan jenis mineral klinoptilolit yaitu pada 2θ di daerah 9,907; 22,389; 22,748; 28,041; dan 30,027°. Terjadi pergeseran puncak pada 2θ  di daerah 28,041° untuk ZAL menjadi 27,802° pada OH-ZAL 0,5 M dan juga terjadi penurunan intensitas. Hal ini menunjukan adanya interaksi antara zeolit dengan KOH lalu terbentuk K2O. Terbentuknya K2O merupakan indikasi bahwa KOH yang terimpregnasi pada permukaan matriks zeolit telah termodifkasi melalui proses kalsinasi. Hasil FTIR menunjukkan semakin tinggi konsentrasi KOH maka vibrasi pada gugus fungsi O-H juga meningkat namun vibrasi pada gugus fungsi T-O menjadi menurun. Biodiesel dengan yield tertinggi diperoleh pada katalis OH-ZAL 2 M yaitu 20,25% dengan kandungan metil ester oktadekanoal 38,59%, pentadekanoat 25,26%, linoleat 9,22%, dan metil ester lainnya dengan persentase kecil. Viskositas biodiesel sebesar 0,95 mm2/s pada 40°C

Reusability of Photocatalytic CoFe2 O4@ZnO Core–Shell Nanoparticles for Dye Degradation

The reusability of CoFe2 O 4 @ZnO core–shell nanoparticles (NPs) for the photocatalytic degradation of methylene blue (MB) under UV radiation was successfully investigated. CoFe 2 O 4 @ZnO NPs with various CoFe2 O 4–to–ZnO concentration ratios were synthesized as magnetic photocatalysts. The X-ray diffraction spectra showed that the NPs had a cubic spinel ferrite phase structure and a hexagonal wurtzite phase of ZnO. Fourier-transform infrared spectra showed the presence of Moct -O, Mtet -O, and Zn–O at 593, 347–389, and 410–429 cm−1 , respectively. The CoFe 2 O 4 @ZnO NPs had a saturation magnetization of approximately 30 emu g−1 and a coercivity of approximately 280 Oe. The absorbance spectra showed that the absorbance peak of the CoFe 2 O 4 @ZnO NPs broadened and shifted to the right (higher wavelength) with increasing ZnO concentration. The CoFe 2 O 4 @ZnO NPs with higher ZnO concentrations exhibited higher photocatalytic activities and degradation rates. The enhancement of MB degradation can be attributed to the formation of an internal structure between CoFe 2 O 4 and ZnO. The degradation rate of CoFe2 O 4 @ZnO decreased slightly after each successive recycle. The results indicated that the recycled CoFe2 O 4 @ZnO NPs could be reused three times for photocatalytic degradation. As there is no significant decrease in the photocatalytic degradation after four successive recycles, the CoFe 2O 4 @ZnO NPs are suitable for application in dye degradation. © 2022 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/ by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cite

Photocatalytic mechanism and properties of recyclable hybrid magnetic/semiconductor nanocomposites synthesized via green route for organic dye degradation

The investigation of the efficiency of recycling, rapid separation, high catalytic performance of photocatalyst materials, and the properties of the material after the photocatalytic process (after use) are considered important for photodegradation applications. Green-synthesized hybrid magnetic/semiconductor nanocomposites utilizing Moringa oleifera leaf extract exhibit excellent photocatalytic performance and reusability under ultraviolet (UV) irradiation. In this study, CoFe2O4/TiO2 nanocomposites were investigated as magnetic/semiconductor photocatalysts. The properties of the green-synthesized nanocomposites before and after the photocatalytic process (recycled photocatalyst) were investigated using UV–visible spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, X-ray fluorescence, Fourier transform infrared spectroscopy, and vibration sample magnetometry. The optical bandgap energies before and after the formation of the nanocomposites were 3.8 and 3.9 eV, respectively. The typical organic pollutant methylene blue was completely degraded within 2 h with an efficiency of 97.4% using the nanocomposites. The crystallite sizes of the nanocomposites before and after use were 11.1 and 10.5 nm, respectively. The magnetic hysteresis curve also showed that, after use, the nanocomposites had a saturation magnetization of 10.6 emu/g and coercivity of 90 Oe. The optical properties, crystal structures, magnetic properties, and morphologies indicated that the nanocomposites were the same as the prepared nanocomposites and retained the same photocatalytic ability after use. Hence, it can be concluded that the green-synthesized hybrid magnetic/semiconductor nanocomposites deliver excellent catalytic performance, and we believe that our findings provide a new platform for efficient photocatalytic applications

Green synthesis of CoFe2O4/ZnS composite nanoparticles utilizing Moringa Oleifera for magnetic hyperthermia applications

The development of targeted cancer therapies is crucial to reducing harmful patient side effects. The incorporation of magnetic and fluorescent nanoparticles as heat mediators in magnetic hyperthermia is a novel and efficient strategy. This study investigated the potential of CoFe2O4/ZnS composite nanoparticles, successfully fabricated using a green synthesis method with Moringa oleifera leaf extract, as magnetic hyperthermia agents. X-ray diffraction spectra demonstrated the existence of the CoFe2O4 cubic spinel ferrite and ZnS cubic zinc-blend phases in the composite nanoparticles. The average particle sizes of CoFe2O4 and CoFe2O4/ZnS were 12 and 17 nm, respectively. The peak at 1406-1411 cm−1 indicated the incorporation of ZnS on the surfaces of the CoFe2O4/ZnS composite nanoparticles through the SO functional group. The UV–visible spectra showed that the bandgap increased from 3.7 to 4.5 eV with increasing ZnS content. Magnetic property studies indicated that the coercivity and saturation magnetization of the CoFe2O4/ZnS composite nanoparticles were lower than those of the CoFe2O4 nanoparticles but still showed ferromagnetic characteristics. Heating properties were investigated by measuring the specific absorption rate (SAR) in an alternating magnetic field at various ZnS contents. The SAR of the CoFe2O4 composite nanoparticles was 85.7 mW/g while that of the CoFe2O4/ZnS composite nanoparticles increased from 87.8 to 132.9 mW/g with increasing ZnS content. Results indicate that green-synthesized CoFe2O4/ZnS composite nanoparticles are promising candidates for magnetic hyperthermia applications in cancer therapy

Magnetically separable and reusable Fe3O4/chitosan nanocomposites green synthesized utilizing Moringa oleifera extract for rapid photocatalytic degradation of methylene blue

This study focused on the green synthesis of Fe3O4/Chitosan (Cs) nanocomposites using Moringa oleifera leaf extract, which showed good photocatalytic activity when exposed to ultraviolet (UV) irradiation. X-ray diffraction spectrum of Fe3O4/Cs informs the cubic inverse spinel and has crystallite size in the 10.1 – 11.7 nm range. The crystallite size also increased with the increase of Cs mass. The morphology of Fe3O4 and Fe3O4/Cs was nearly spherical. The transmission electron microscope showed the most uniform size of nanocomposites at around 17.1 nm. The Fourier transform infrared spectrophotometer result identified Fe-O in the 576–583 cm−1 range, indicating that Fe3O4 successfully bonded to Cs. Other functional groups, including O–H, C–H, C–O, C–O–C, and NH2, were also found, indicating that the formation of Cs was effective. The element composition of Fe3O4 is Fe (70.9 %) and O (29.1 %). Meanwhile, Fe3O4/Cs (4:4) is 47.9 %, 36.4 %, 11.3 %, and 4.4 % for Fe, O, C and N, respectively. The hysteresis curve indicated that Fe3O4 and Fe3O4/Cs nanocomposites have soft ferromagnetic properties. Meanwhile, the saturation magnetization of Fe3O4 and Fe3O4/Cs (4:2) nanocomposites are 54.0 and 42.3 emu/g, respectively. Peaks are seen in the UV–visible absorption spectrum of Fe3O4 and Fe3O4/Cs nanocomposites between wavelengths 365–377 nm. The optical band gap energy (Eg) of Fe3O4 and Fe3O4/Cs (4:2) are 3.4 and 3.0 eV, respectively. As the mass of Cs increases, the band gap energy decreases. Under UV light irradiation, 50 mg of Fe3O4 and Fe3O4/Cs were analyzed on 7 ppm of methylene blue, pH = 4. The maximum photocatalytic activity Fe3O4/Cs (4:3), achieved an impressive degradation rate of 94.7 % after 120 min of irradiation. The magnetically separable capability means nanocomposites can be recycled and reused five times with high degradation. Furthermore, Fe3O4/Cs has the potential to be a low-cost and environmentally friendly reusable photocatalyst for rapid wastewater degradation