Papers by Jesús Alberto Ramos Ramón
American Journal of Engineering and Applied Sciences, 2016
Well crystalline, near-stoichiometric zinc oxide nanostructures of different morphologies are fab... more Well crystalline, near-stoichiometric zinc oxide nanostructures of different morphologies are fabricated in large scale, utilizing a simple, cost effective mechanochemical synthesis in absence of solvent. Effects of ionic and nonionic surfactants along with the concentration of hydrolyzing agent on the evolution of nanostructure morphology have been studied. It has been observed that while a cationic surfactant such as Cetyltrimethylammonium Bromide (CTAB) favors the nanostructures to growth along their polar c-axis, a nonionic surfactant such as Polyvinylpyrrolidone (PVP) reduces their preferred c-axis growth. Increase of hydrolyzing agent in the reaction mixture enhances the growth rate of the nanostructures. The nanostructures have been tested for photodegradation of anionic dye molecules such as Methylene Blue (MB). All the nanostructures manifest high photocatalytic performance. Apart from morphology, the specific surface area, crystal plane orientation and the concentration of basic sites at surface are seen to contribute significantly to the photocatalytic performance of the zinc oxide nanostructures.
Sn-doped indium oxide micro-and nanoparticles with different Sn contents (0–15 wt% nominal) were ... more Sn-doped indium oxide micro-and nanoparticles with different Sn contents (0–15 wt% nominal) were grown by vapor-transport method. Effects of Sn content on the morphology and defect evolution in the crystalline particles were studied using scanning electron microscopy, micro-Raman, cathodoluminescence (CL), and UV–vis optical absorption spectroscopy techniques. It has been observed that Sn doping enhances the direct band gap energy of In2O3 micro- /nanostructures, modifies their morphology and
electronic defect structures. By controlling the concentration of Sn, CL emission behavior of In2O3 nanostructures can be controlled systematically.
Octahedral shaped single crystalline undoped and Ga-doped indium oxide nano-and microcrystals wer... more Octahedral shaped single crystalline undoped and Ga-doped indium oxide nano-and microcrystals were fabricated using vapor-solid growth process. Effects of Ga doping on the crystallinity, defect structure, and optical properties of the nano-/microstructures have been studied using scanning electron microscopy, microRaman spectroscopy, transmission electron microscopy and cathodoluminescence spectroscopy. It has been observed that incorporation of Ga does not affect the morphology of In2O3 structures due to its smaller ionic radius, and similar oxidation state as that of In. However, incorporation of Ga in high concentration (~3.31 atom %) causes lattice compression, reduces optical band gap and defect induced CL emissions of In2O3 nano-/microcrystals. The single crystalline Ga-doped, In2O3 nano-/microcrystals with low defect contents are promising for optoelectronic applications
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Papers by Jesús Alberto Ramos Ramón
electronic defect structures. By controlling the concentration of Sn, CL emission behavior of In2O3 nanostructures can be controlled systematically.
electronic defect structures. By controlling the concentration of Sn, CL emission behavior of In2O3 nanostructures can be controlled systematically.