In the present study, morphology, size distribution, structure, biocompatibility and magnetic properties of potassium ferrite nanoparticles （KFeO2 NPs）, synthesized by conventional sol-gel method have been reported....In the present study, morphology, size distribution, structure, biocompatibility and magnetic properties of potassium ferrite nanoparticles （KFeO2 NPs）, synthesized by conventional sol-gel method have been reported. The formation of spherical nanoparticles with orthorhombic structure has been confirmed by scanning electron microscopy and X-ray diffraction. The particle size, as obtained by transmission electron microscopy has been found to be in the range of 4-7 nm. Further, the size distribution has been scrutinized using Analyse-it software, where a platykurtic feature in the size distribution was observed. Fourier transform-infrared spectroscopy and thermogravimetric analysis showed the formation of metal （Fe, K） bonds at Neel temperature of 337℃. Vibrating sample magnetometer analysis revealed the superparamagnetic behaviour of the synthesized KFeO2 NPs, with saturation magnetization of 25.72 emu/g. In vitro cytotoxicity test, using MTTassay, on T cell lines （Jurkat cells） showed that KFeO2 NPs are biocompatible at a particle concentration of 100μg/ml.展开更多
In this communication, the synthesis and structural, morphological, optical, and photo-electrochemical properties of TiO2 and CaCO3/TiO2 nanoparticles as well as their applications in dye sensitized solar cells （DSSC...In this communication, the synthesis and structural, morphological, optical, and photo-electrochemical properties of TiO2 and CaCO3/TiO2 nanoparticles as well as their applications in dye sensitized solar cells （DSSCs）, have been reported. In an X-ray diffraction pattern of CaCO3/TiO2 nanoparticles, the peak at 29.41 ° of CaCO3 has been detected, demonstrating its coating on the surface of TiO2, which is further verified using high resolution-transmission electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The strong quenching in photoluminescence emission, in the case of CaCO3/TiO2 nanoparticles, has been attributed to the decrease in recombination rate of photo-generated electron-hole pairs. In the case of UV-visible reflectance spectra, the absorption edge for CaCO3/TiO2 nanoparticles has slightly been found to be blue-shifted as compared to bare TiO2 nanoparticles, which corresponds to an increase in energy band gap of the former. The dye desorption studies reveal that CaCO3/TiO2 electrodes adsorbed more dye than the bare TiO2 electrode. CaCO3/TiO2 based DSSC show improved photo- electrochemical properties compared to the bare TiO2 based DSSC as CaCO3 coating on mi02 forms an energy barrier, and, consequently suppressing the charge recombination, and, thus, improving the overall energy conversion efficiency （η） from 0.46% to 1.44% under the illumination of simulated light of 100 mW/cm2.展开更多
基金Department of Science and Technology,Government of India New Delhi for awarding her INSPIRE Fellowship
文摘In the present study, morphology, size distribution, structure, biocompatibility and magnetic properties of potassium ferrite nanoparticles （KFeO2 NPs）, synthesized by conventional sol-gel method have been reported. The formation of spherical nanoparticles with orthorhombic structure has been confirmed by scanning electron microscopy and X-ray diffraction. The particle size, as obtained by transmission electron microscopy has been found to be in the range of 4-7 nm. Further, the size distribution has been scrutinized using Analyse-it software, where a platykurtic feature in the size distribution was observed. Fourier transform-infrared spectroscopy and thermogravimetric analysis showed the formation of metal （Fe, K） bonds at Neel temperature of 337℃. Vibrating sample magnetometer analysis revealed the superparamagnetic behaviour of the synthesized KFeO2 NPs, with saturation magnetization of 25.72 emu/g. In vitro cytotoxicity test, using MTTassay, on T cell lines （Jurkat cells） showed that KFeO2 NPs are biocompatible at a particle concentration of 100μg/ml.
基金the University Grants Commission(UGC)for the research funding vide sanction letter No.F.No.39-533/2010(SR)of January 2011
文摘In this communication, the synthesis and structural, morphological, optical, and photo-electrochemical properties of TiO2 and CaCO3/TiO2 nanoparticles as well as their applications in dye sensitized solar cells （DSSCs）, have been reported. In an X-ray diffraction pattern of CaCO3/TiO2 nanoparticles, the peak at 29.41 ° of CaCO3 has been detected, demonstrating its coating on the surface of TiO2, which is further verified using high resolution-transmission electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The strong quenching in photoluminescence emission, in the case of CaCO3/TiO2 nanoparticles, has been attributed to the decrease in recombination rate of photo-generated electron-hole pairs. In the case of UV-visible reflectance spectra, the absorption edge for CaCO3/TiO2 nanoparticles has slightly been found to be blue-shifted as compared to bare TiO2 nanoparticles, which corresponds to an increase in energy band gap of the former. The dye desorption studies reveal that CaCO3/TiO2 electrodes adsorbed more dye than the bare TiO2 electrode. CaCO3/TiO2 based DSSC show improved photo- electrochemical properties compared to the bare TiO2 based DSSC as CaCO3 coating on mi02 forms an energy barrier, and, consequently suppressing the charge recombination, and, thus, improving the overall energy conversion efficiency （η） from 0.46% to 1.44% under the illumination of simulated light of 100 mW/cm2.
