Papers by Keyword: Nanorod

Abstract: A two-stage hydrothermal method was used to prepare rapid-switching electrochromic WO₃/ZnO composite electrodes. The morphology of the nanorods was altered by changing the precursor concentration. A higher precursor concentration inhibited the growth of crystals and declined the crystallinity of nanorods. Nanorods with a diameter of 48 nm, height of 92.5 nm, and transmittance greater than 80% were grown when the precursor concentration in the second step was 1.5 times that in the first step. The electrochromic electrode demonstrated rapid coloring and bleaching speeds (5 and 0.8 s, respectively), which were faster than those of the electrode prepared using the one-stage process.

Abstract: A resistive ethanol gas sensor with a high sensitivity has been proposed. The fabricated gas sensor has a very promising response and recovery at room temperature. The proposed sensor has been fabricated by depositing sensitive nanostructured material on printed circuit board interdigitated electrodes. As the sensitive material, ZnO nanorods of high uniformity have been synthesized by hydrothermal method and then decorated by PbS nanoparticles. The synthesized decorated nanorods were characterized by X-ray diffraction and scanning electron microscope which confirmed the formation of the desired nanostructures. The ethanol gas sensing properties of the ZnO nanorods decorated with PdS nanoparticles was measured in a test chamber. The minimum ethanol concentration detected by the sensor has been 10 ppm. The results showed the higher sensitivity of the proposed sensor to the ethanol at room temperature compared to similar works.

Abstract: Dye-sensitized solar cells (DSSCs) is a part of the third-generation family which have been developed under substantial research for almost three decades due to their low-cost fabrication, low toxicity, and can be manufactured on the flexible substrate. However, the challenge for the improvement of current DSSC is still opened, especially in the scope of efficiency, stability, and platinum (Pt)-free counter electrode. In this work, the incorporation of solution-processed rGO as a replacement for the Pt counter electrode DSSC is demonstrated. The rGO solutions with three different concentrations (1, 3, and 5 wt%) are utilized. The highest power conversion efficiency (PCE) of about 0.1 % is displayed by 5 wt% rGO solution based devices. The results reported in this work exhibited the high potential of solution-processed rGO as an efficient alternative material in the counter electrode of DSSC.

Abstract: CuO nanorods were fabricated by a facile microwave-assisted synthesis method and applied to pseudo-capacitor. The CuO nanorods were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The capacitive behavior of nanorods was investigated by cyclic voltammetry and galvanostatic charge–discharge measurements. Electrochemical experiments reveal that CuO nanorods demonstrate better capacitance performance than granular CuOs prepared by chemical precipitation method. The CuO nanorods have a high specific capacitance of 317 F/g at a current density of 1 A/g and a fairly good cyclic stability.

Abstract: In this Research, a ball mill procedure was used to prepare a nanopowder from a cement dust material supplied by Cement Factory for reinforcing the oil well cement through using it as a partial replacement of oil well cement class G by a weight percentage of (0.25 to 1%) and nanorod ZnO with the same percentages. The mix with a water to cement ratio was kept at 0.44. Characterizations of the structured prepared samples were done, density and compressive strength and free water. Experimental outcomes display that the generated nanopowder have a particle size of (100 nm) and that the structural properties improved significantly with the development phase of calcium silicate hydration C-S-H. Density and compressive strength significantly improved with lower free water. That makes it proper as smart cement for the oil well applications.

Abstract: Products formed in the discharge region of the DC arc between graphite electrodes in water were studied. Whereas one of them was grown on a cathode and kept whole, the other is arose by erosion of electrodes in powder form and sank or floated in the surrounding water. The structure of the products was studied by SEM and SEM EDX analysis. The whole parts grown on the cathode were made up three different components: (i) almost spherical tiny particulates; (ii) long and narrow linear parts; and (iii) macro particulates of gigantic size. We have identified the size distributions and the number densities for these component parts in the sample as well their mechanical features. The powder samples included bulk particulates of carbon sheets and linear structures, like a thread. The study shows that the long linear structures in the powder sample are formed by the scrolling of carbon layers whereas the ones deposited are formed by a growth mechanism

Abstract: Anode surface plays important role for extracellular electron transfer (EET) of exoelectrogenic microbes in microbial fuel cell (MFC). In this report, the electrochemical performance of a TiO₂ nanorod array modified carbon paper electrode (TiO₂ NRs/CP) is greatly improved by controlled chemical etching process. The etching process keeps the array morphology but yields obvious hollows on tops of TiO₂ nanorods. The etched electrode (TiO₂ NRs-HOT/CP) exhibits better hydrophilicity than carbon paper (CP) and TiO₂ NRs/CP electrode as seen from smaller contact angle (CA) and more attached microbes S.loihica PV-4. Meanwhile, the hollows allow higher local concentration of microbial self-secreted flavins that can act as electron mediators for interfacial electron transfer of PV-4 through in-direct pathway. Accordingly, PV-4 produces larger current density at TiO₂ NRs-HOT/CP electrode with maximum current density of 0.038 mA cm ^–2, which was much higher than that at CP electrode, and almost five times higher than that at un-etched TiO₂ NRs/CP electrode.

Abstract: The formation of cobalt (Co) doped zinc oxide (ZnO) as photocatalyst for photodegradation of methyl orange dye was investigated. The ZnO photocatalyst was produced with different concentration of Co by using sol gel method. The hexagonal wurtzite and zincite structure were successfully formed through this method. The morphological observation of nanorod and nanodisk structure formed was done by Field Emission Scanning Electron Microscope (FESEM). While, the structural properties of Co doped ZnO were identified by X-ray Diffraction (XRD) and Raman spectroscopy. The degradation performance of methyl orange was assessed and performance of photocatalytic activity was correlated to the amount of dopant level and oxygen vacancy of photocatalyst. There is an optimum amount of Co that can be doped into ZnO nanostructure in order to provide better degradation of methyl orange.

Abstract: Vertically aligned nanorods ZnO have been deposited hydrothermally on the pre-coated ZnO seeded-glass substrates. Enhanced vertical alignment is achieved as a result of combined film post-treatments. Dipped-drawn and immersed-washing the as-synthesized ZnO films in water as well as quenching of the hydrothermal were proposed to hinder excessive deposition and engineer the growth of ZnO nanorods. The XRD patterns shows suppressed growth of ZnO crystallite along (101) with increased textural coefficients on (002), TC₀₀₂, from 3.94 to 5.23. Dense vertically aligned bundles of ZnO nanorods may reach up to 0.75 μm length. Bandgap energy of the resulted ZnO nanorod thin films were ranging from 3.69 to 3.79 eV, wider than those of bulk ZnO. Hydrothermal technique with simple post-treatments of immersed-washing and hydrothermal quenching has offered robust and efficient method to prepare vertically-aligned 1-D ZnO nanorods potential as photoanodes for dye-sensitized solar cells.

Abstract: One dimensional (1-D) organic materials have a bright prospect in the field of optoelectronics. Intrigued by these, 1-D uniform sub-micrometer tris-(8-hydroxyquinoline) gallium (GaQ₃) rods were prepared with surfactant by an extremely facial method. The GaQ₃ rods with hexagonal cross sections had excellent crystallinity and optical properties. The measurement of the absorption spectrum showed that there was an obvious blue shift comparing with the GaQ₃ film. This can be explained by that the molecular packing in the α-phase rods has a looser interligand spacing compared with the GaQ₃ film, consequently resulting in reduced orbital overlap and larger energy gap.