Papers by Keyword: Nanorod

Abstract: Nanostructures materials were prepared from rice husk ash by carbon charcoal assisted. The rice husk ash mixed with coconut shell charcoal and Cu-Sn powder as the source materials. The mixtures materials were heated at 1100 °C under atmosphere of nitrogen with flow rate of 1 L/min. After the temperature was cool down, the prepared products were characterized by the stereo microscope, scanning electron microscope (SEM) and X-ray diffraction (XRD). The SEM images showed nanostructures materials such as nanoparticles, nanorods and nanowires. The XRD patterns indentified that the consisted of nanostructures materials were SiO₂-CuO phase.

Abstract: A core-shell nanocomposite particle with polystyrene sphere core and polythiophene overlayer shell was synthesized through thiophene chemical oxidative polymerization using uniquely structured polystyrene latexes template. The morphology of polythiophene shell, which has nanorods shaped or featureless surface morphology, can be simply controlled through varying the dosage and feeding methods of oxidizers.

Abstract: The main development of ZnO nanorods (NRs) is focused on the gold catalyst and heteroepitaxial approach.However, the presence of Au may generate undesired deep level traps in the ZnO bandgap, which could be very harmful to the performance of transistors. The objective of this study is to synthesize ZnO NRs via homoepitaxial growth without using foreign catalyst by Chemical Vapour Deposition (CVD) technique. The growth of catalyst-free ZnO NWs at different CVD synthesis parameters such as amount of Zn powder, substrate location and synthesis duration on the catalyst-free ZnO NRs were studied systematically. The effect of these parameters on the size and areal density of ZnO NRs provided a better understanding on the growth mechanism of NRs via the Vapour-Solid (VS) mechanism.

Abstract: An ultraviolet (UV) shielding agent based on Fe-doped zinc oxide nanorods (ZnONRs) was synthesized by ex-situdoping using spray pyrolysis technique. These Fe-doped ZnO NRs could reduce the inherent photocatalytic activity of zinc oxide while still maintaining their ultraviolet filtering capability. In this work, the effect of doping duration by spray pyrolysis technique on the optical property and photocatalytic efficiency of ZnO NRs was studied. The room temperature photoluminescence (PL) analysis on the Fe-doped ZnO NRs indicates the red-shift of violet emission peak, i.e. from 378.97 nm (undoped) to 381.86 nm (60 mins.doping). Besides, the reduction of I_UV/_Vis ratio of PL reveals that the ex-situ Fe doping deteriorated the crystal quality of ZnO NRs. The photocatalytic study shows that the rate constant of Fe-doped ZnO NRs was smaller than the undoped ZnO NRs. It means that the Fe-doped ZnO NRs were less effective in degrading the RhB solution.

Abstract: Nanomaterials research has become a major attraction in the field of advanced materials research in the area of Physics, Chemistry, and Materials Science. Biocompatible and chemically stable magnetic metal oxide nanoparticles have biomedical applications that includes drug delivery, cell and DNA separation, gene cloning, magnetic resonance imaging (MRI). This research is aimed at the fabrication of magnetic cobalt oxide nanoparticles using a safe, cost effective, and easy to handle technique that is capable of producing nanoparticles free of any contamination. Nanostructured Cobalt oxide powder was prepared by sonication method using ultrasonicator. Effect of sonication for different time intervals, on the morphology of cobalt oxide nanostructures was extensively studied. The morphology of the nanorods were very much affected by the sonication time, it was found that with an increase in sonication time, the length of the nanorods seem to considerably increase at the same time an agglomeration effect comes in to action and the rods form bundle like structures. These cobalt oxide nanorods were characterized using X-ray Diffraction characterization (XRD) and it revealed a cubic structure. Weight percentage of cobalt oxide was confirmed by thermo gravimetric analysis (TGA).

Abstract: Low-dimension materials such as nanobelts, nanowires and nanorods are being investigated for their superior properties and numerous applications. Among them, one-dimensional semiconductor ZnO, representing one of the most important low dimensional materials, finds its applications in many different fields such as sensors, solar cells, IR detectors, microelectronics, etc. Synthesis of nanostructures without any catalytic template, or using the self-catalytic behavior of the material would be of interest. In this work, ZnO nanorods have been synthesized by simple two step process without using any catalyst. This method provides an easy way to produce nanostructured metal oxides under normal conditions. The prepared samples were characterized by studying their structural, optical and morphological properties using X-Ray Diffraction, Photoluminescence and Scanning Electron Microscopy. The diameter of the prepared nanorods were around 20-30 nm¬. The room temperature Photoluminescence spectra of the ZnO nanorods shows a broad visible emission around 450–530 nm.

Abstract: Ni-doped titanate nanorods were synthesized from anatase TiO2 powder and Ni nitrate using a one-step hydrothermal reaction in alkaline solution. The nanorods are straight with lengths a few micrometer and diameters between 80 and 120 nm. The Ni-doped nanorods have the similar structure as hydrogen titanate nanorods of monoclinic structure. Magnetic measurement revealed that Ni-doped titanate nanorods are ferromagnetism at 300K. Electron paramagnetic resonance were studied and the spectra showed that a broad asymmetric signal and a signal in low field appeared due to the Ni ions incorporated into the titanate lattice. The results suggest that Ni-dopants play an important role in the ferromagnetism. The ferromagnetic response could be attributed to Ni intercalated into the titanate lattice.

Abstract: We investigated the effect of immersion time on optical, electrical properties and surface morphology of nanostructured Aluminium (Al) doped Zinc Oxide (ZnO) thin films prepared by immersion technique. UV-Vis-NIR spectra indicate that the transmittance of the samples decrease with immersion time. Electrical properties study reveals the nanostructured Al doped ZnO thin film at 1 hr shows the lowest resistivity compared to other samples. Surface morphology results as characterized by scanning electron microscope (SEM) show that the Al doped ZnO nanorods quantity increased with immersion time.

Abstract: This paper describes a one-step hydrothermal synthesis of rod-shaped HgTe nanocrystals (NCs). X-ray powder diffraction (XRD), field scanning electron microscopy (FE-SEM), transition electron microscopy (TEM) and energy-dispersive X-ray analysis (EDX) have been used to characterize the HgTe NCs. The length, diameter, surface roughness and the aspect ratio of the HgTe nanorods are well controlled through Te precursor, reaction time and reductant.

Abstract: Amorphous phase MnOx/TiO2 catalysts were prepared by two different methods, their catalytic activities for low temperature selective catalytic reduction (SCR) of NOx with NH3 in the presence of excess oxygen were investigated. The catalysts were characterized by XRD, XPS and HRTEM. The results showed that the catalyst prepared by soft template method had better catalytic active than those prepared by sol-gel method, its catalytic property could reach 98.2% at 200°C. From the microstructure characterization, it could be known that the catalyst prepared by soft template had the shape of nanorod, this shape was contributed to the dispersion of the manganese oxides and possessed higher surface lattice oxygen concentration. Furthermore, narrow slit-shaped pores associated with rod-like particles could provide efficient transport pathways to reactant molecules and products. Due to these, the catalyst performed catalytic active very well.