Ashok B. Gadkari; Tukaram J. Shinde; Appaso A. Wali; Pramod N. Vasambekar
Abstract
Nanocrystallite ferrites samples with general formula Mg1-xCdx Fe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1) were prepared by oxalate co-precipitation method from high purity sulphates. The samples were characterized by XRD, SEM and FT-IR techniques. The phase identification of powder reveals single phase cubic ...
Read More
Nanocrystallite ferrites samples with general formula Mg1-xCdx Fe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1) were prepared by oxalate co-precipitation method from high purity sulphates. The samples were characterized by XRD, SEM and FT-IR techniques. The phase identification of powder reveals single phase cubic spinel nature of materials. The gas sensing properties were studied for ethanol (C2H5OH), liquid petroleum gas (LPG) and chlorine (Cl2). The MgFe2O4 is sensitive to LPG (~ 80%) followed by Cl2 (~75%) and less to ethanol (~ 58%) at an operating temperature of 225oC. The sample with x = 0.4 has highest sensitivity at operating temperature 225oC for LPG (~ 78%). It shows good sensitivity at operating temperature at 198oC for Cl2 (~75%) and ethanol (~ 65%). The CdFe2O4 sensor (x=1) exhibits very high sensitivity (85%) and good selectivity to ethanol than other tested gases such as LPG (~ 35%) and Cl2 (~ 30%). The response and recovery time decreases with increase in Cd2+ content for LPG, Cl2 and ethanol. The shorter response is observed to CdFe2O4 for LPG, Cl2 and ethanol.
Rohit R. Powar; Ashok B. Gadkari; Pravina B. Piste; Dnyandevo N. Zambare
Abstract
Nanoparticles of Zinc substituted Cobalt ferrite powders having general formula ZnxCo1-xFe2O4 (x = 0, 0.25, 0.5, 0.75, 1.0) have been produced by using analytical grade nitrates and hexadecyltrimethylammonium bromide (CTAB) as structure directing reagent via Chemical co-precipitation method. The structure ...
Read More
Nanoparticles of Zinc substituted Cobalt ferrite powders having general formula ZnxCo1-xFe2O4 (x = 0, 0.25, 0.5, 0.75, 1.0) have been produced by using analytical grade nitrates and hexadecyltrimethylammonium bromide (CTAB) as structure directing reagent via Chemical co-precipitation method. The structure and morphology of prepared polycrystalline ferrite nanoparticles were investigated by X-ray diffraction (XRD), Fourier Transform Infrared Radiation (FTIR) and Scanning electron microscopy (SEM) respectively. Thermogravimetric differential analysis (TG/DTA) technique gives information about ferrite phase formation occurs beyond 450 ºC. The XRD analysis confirms the establishment of the cubic spinel structure with the presence of minor secondary phase of α-Fe2O3 (hematite) at a calcination temperature of 650 ºC. The polycrystalline mixed zinc cobalt ferrite nanoparticles showed a dual phase and crystallite size lies in the range 6-11 nm. FE-SEM microstructure shows the nearly spherical polycrystalline nanoparticles with a particle size in between 0.11-0.20 µm. The FT-IR spectra display two significant strong absorption bands nearby in the range of 400 cm-1 and 600 cm-1 on the tetrahedral and octahedral sites respectively. Copyright © 2018 VBRI Press.
Mrinal K Adak; Sujoy Chakraborty; Shrabanee Sen; Debasis Dhak
Abstract
Zirconium-aluminium modified iron oxide nano adsorbent was synthesized using chemical route using zirconyl nitrate, aluminium nitrate, ferric nitrate and triethanol amine. The precursor materials were calcined at 900oC for 4 h to obtain a carban free nano-adsorbent. XRD of the calcined powder was ...
Read More
Zirconium-aluminium modified iron oxide nano adsorbent was synthesized using chemical route using zirconyl nitrate, aluminium nitrate, ferric nitrate and triethanol amine. The precursor materials were calcined at 900oC for 4 h to obtain a carban free nano-adsorbent. XRD of the calcined powder was performed to detect the phase and to estimate the crystallite size. Fluoride removal tests were performed using synthesized fluorinated aqueous solutions of 3 ppm, 5 ppm and 10 ppm. The adsorbent dose was considered 15 mints, 30 mints, 45 mints and 60 mints while adsorbent dose were varied from0.1 mg to 0.3 mg for every 100 ml fluorinated aqueous solution. FTIR spectroscopy of the nano-adsorbent was studied before and after fluoride removal. Percentage of fluoride removal was checked for at least three cycles using the same adsorbent. Fluoride concentration of treated aqueous solution was studied using UV-Visible spectrometer using standard zirconium alizarin S solution. Maximum % of fluoride removal was observed up to 99.9% for an adsorbent dose 0.3 mg for a contact time of 15 minutes at 3 ppm fluoride concentration. However, the adsorbent dose for highest % of fluoride removal depends highly on the contact time and initial fluoride concentration and they were found to be very selective. The synthesized nano-sdsorbent could be used commercially for effective fluoride removal from fluorinated water for drinking purpose. Copyright © 2017 VBRI Press.
