Preparation of a high surface area zirconium oxide for fuel cell application

Abstract Stable and high surface area zirconium oxide nanoparticles have been synthesised by means of the hydrothermal method. The Brunauer–Emmett–Teller results show that a high surface area of 543 m2/g was obtained in the hydrothermal process, having a high porosity in nanometre range. The hydrothermal method was applied at 120 °C by using an autoclave with a Teflon liner at an ambient pressure for 48 h. High-resolution scanning electron microscopy shows the different morphologies of zirconia nanoparticles, which could be categorised as one-dimensional and zero-dimensional, as they had a high crystallite orientation, which was also confirmed by the X-ray diffraction (XRD). The mixture of two types of cubic phases in one sample was obtained from XRD and confirmed by the zirconia nanostructure, showing the stable phase of fluorite, which has full cubic symmetry (Im-3m), and also an Arkelite zirconia nanostructure, showing the stable phase of fluorite, which has full cubic symmetry (Fm-3m). The XRD results also show the different structure orientations of face-centred cubic and body-centred cubic in one sample

Localized surface plasmon resonance sensing of Trenbolone acetate dopant using silver nanoparticles

Abstract In this work, localized surface plasmon resonance (LSPR) sensing as applicable in the detection of Trenbolone acetate dopant is demonstrated. We show that the LSPR of the Trenbolone acetate/silver nanoparticle (Tren Ac/AgNPs) complex is sensitive to changes in the adsorbent concentration. The results show an average redshift of + 18 nm in the LSPR peak with variations in intensity and broadening behavior of the LSPR band of the Tren Ac/AgNPs complex. AgNPs were synthesized using laser ablation in liquid (LAL) technique with water as the solvent. UV–Vis spectroscopy was used for absorbance measurements and particle size and morphology were monitored using scanning electron microscopy (SEM). The aggregation behavior of the Tren Ac/AgNPs complex was monitored using energy-dispersive X-ray spectroscopy (EDS). Molecular Electrostatic Potential (MEP) and the HOMO–LUMO orbitals of the optimized Trenbolone acetate structure were obtained using Density Function Theory (DFT). The molecule was optimized at the B3LYP level of theory using the 6–311 basis set carried out using the Gaussian 09 software package. The results showed that O2− is Trenbolone acetate’s active site that would interact with Ag+ to form a complex that would influence the plasmon behavior. The results presented in this work demonstrate the feasibility of LSPR for anabolic androgenic steroid detection

Natural Dye Sensitizer for Grӓtzel Cells: Sepia Melanin

Research Article published by Science and Education Publishing Vol. 3, No. 1, 2015The efficiency of Grätzel cell can be further improved by the anchoring groups, such as COOH to be adsorbed onto the TiO2 surface with a large electronic coupling. Some of the most efficient sensitizers are synthetic dyes including transition metal coordination compounds such as Ruthenium polypyridyl complexes because of their highly efficient metal-to-ligand charge transfer, suitable ground and excited state energy levels with respect to titanium dioxide conduction band energy. They also have intense and wide range absorption in whole visible range. Even if they present such attractive features, their synthesis process is costly and complicated and they are not environment friendly because they contain heavy rare metals which are undesirable from the point of view of environmental conservation aspects. Natural dye can be the best alternative as they have acceptable efficiency in comparison to that one of transition coordination compounds and their extraction can be done by simple procedures from flowers, leaves, fruits, animals and other natural products. Melanin as the major component Sepia Officinalis ink pigment cause strong interactions with the hydroxyl groups of a TiO2. Melanin possesses a broad band absorbance in UV and visible range up to infrared. It also possesses the COOH and OH groups which would be free to bind to the surface of TiO2. Moreover, melanin polymer has interesting properties such as a considerable spectral absorbance width due to the high degree of conjugation of the molecule. This paper reports results from X-ray diffraction (XRD), UV-Vis as well as Raman spectroscopy of sepia melanin for Grätzel cell application

Morphological and Chemical Composition Characterization of Commercial Sepia Melanin

Research Article published by Science and Education Publishing Vol. 3, No. 1, 2015Melanins are difficult to characterize because of their intractable chemical properties and the heterogeneity in their structural features. Melanin pigments, in fact, are composed of many different types of monomeric units that are connected through strong carbon-carbon bonds. Its high insolubility and undefined chemical entities are two obstacles in its complete characterization. The morphological characterization and particle size distribution for sepia melanin by Scanning Electron Microscopy (SEM) on surface structure and Transmission Electron Microscopy (TEM) to confirm the morphology obtained from SEM was done. Both results show that Sepia melanin is formed by many aggregates agglomerated together. These aggregates are formed also by small spherical granules with different size distributions that have been determined using image-J software. The small granule diameter obtained from different TEM and SEM micrographs were 100-200nm. EDS reveals that C and O were the most abundant in sepia melanin with concentration average concentrations of about 57% and 24% respectively. The major compositions of sepia melanin are C, O, Na, Cl, while the minor are Mg, Ca, K, S and N. From TEM micrograph at high resolution, it was possible to measure the distance between polymers layers of sepia melanin using image-J software and it was 0.323 nm = 3.23 Å