ABSTRACT
Cuprous oxide (Cu2O) nanorod arrays have been prepared via a novel templated electrodeposition process and were characterized for their photocatalytic behavior in nonaqueous photoelectrochemical cells. Zinc oxide (ZnO) nanorod films serve as sacrificial templates for the in situ formation of polymer nanopore membranes on transparent conductive oxide substrates. Nitrocellulose and poly(lactic acid) are effective membrane-forming polymers that exhibit different modes of template formation, with nitrocellulose forming conformal coatings on the ZnO surface while poly(lactic acid) acts as an amorphous pore-filling material. Robust template formation is sensitive to the seeding method used to prepare the precursor ZnO nanorod films. Photoelectrochemical cells prepared from electrodeposited Cu2O films using methyl viologen as a redox shuttle in acetonitrile electrolyte exhibit significant charge recombination that can be partially suppressed by a combination of surface passivation methods. Surface-passivated nanostructured Cu2O films show enhanced photocurrent relative to planar electrodeposited Cu2O films of similar thickness. We have obtained the highest photocurrent ever reported for electrodeposited Cu2O in a nonaqueous photoelectrochemical cell.
ABSTRACT
Zinc oxide films were fabricated by a homemade spray pyrolysis system equipped with an optical setup ensuring the in situ control of the film growth. Zinc acetate (0.1 M) diluted in a mixture of ethanol and water was used as the precursor solution. The ethanol-water molar ratio, gamma, in the precursor solution was varied from 0 to 0.92. The deposition temperature and the pH of the precursor solution were kept at 350 degrees C and 4.5, respectively. X-ray diffraction patterns revealed that films were zincitelike with a grain size depending on the ethanol-water molar ratio in the precursor solution. The interference pattern obtained during film deposition was used to monitor the film roughness; it was found that this is related with those results of surfaces and optical analysis obtained by scanning electron microscopy and spectrophotometric measurements, respectively. The morphology of the ZnO films obtained from gamma equal to either 0 or 0.92 are dense with agglomerates uniformly distributed, whereas the films obtained from gamma equal to either 0.03 or 0.06 are very rough with irregular agglomerates. The films obtained from gamma equal to 0.12, 0.18 and 0.31 are rough. Photoelectrocatalytic results indicated that there is a correlation of the partial molar volume of ethanol with respect to water in the spraying solution, with the photocatalytic efficiency of the ZnO films. We found that the maximum photodegradation of methyl orange in the solution occurs using ZnO films obtained with gamma = 0.12.
ABSTRACT
Informa sobre la implementación de la tecnología de remoción de arsénico bajo irradiación solar (RAOS), comparando los resultados con los obtenidos bajo irradiación con luz ultravioleta (UV) de una lámpara
Subject(s)
Arsenic , Solar Energy , Contaminant Removal , PeruABSTRACT
Se aplico la tecnología de desinfección solar del agua en unidades individuales (DSAUI) a aguas del asentamiento humano Tambo Pariachi en Huaycan, cuyos valores iniciales de contaminación encontrados (Coliformes) indicaban que las mismas no eran aptas para consumo humano. El método empleado es sencillo y económico y podría ser utilizado de manera masiva por la población, como una alternativa para obtener agua potable
Subject(s)
Water Disinfection , Groundwater , Solar Energy , PeruABSTRACT
Los autores presentan un análisis sobre la situación y problemática actual en torno al alcoholismo, desde sus perspectivas de Diagnóstico, Epidemiología y Repercusiones Sociales. El objetivo del trabajo es de seleccionar un Inventario para el diagnóstico del alcoholismo que satisfaga las necesidades de uniformidad de criterios y una fácil aplicación para el estudio del problema. Se escogió el Inventario MALT (Munchener Alkoholismus Test; Feuerlein), el cual se aplicó en un grupo de pacientes alcohólicos y un control, para su validación. Según los resultados demostró tener un alto grado de sensibilidad y especificidad, además permitió conocer un gran número de variables de nuestros pacientes alcohólicos. Se concluye que el MALT es un instrumento altamente sensible y confiable para el diagnóstico de alcoholismo, siendo el principal aporte para las investigaciones futuras en nuestro medio
