6 research outputs found
Realizing near stoichiometric and highly transparent CdS:Mo thin films by a low‐cost improved SILAR technique
No full textINFLUENCE OF Pr2Co7 MAGNETIC NANOMETER PARTICLES ADDITION ON YBa2Cu3Oy SUPERCONDUCTOR MAGNETO-CONDUCTIVITY’S IN FLUCTUATION REGIME.
No full textComparison of the Structural and Morphological Properties of Sn Doped ZnO Films Deposited by Spray Pyrolysis and Chemical Bath Deposition
No full textSimultaneous effect of precursor sources and concentration on structural, morphological and optical properties of ZnO nanostructured thin films for photovoltaic applications
No full textThe collection and transport of charges at the electrodes are the main factors limiting the efficiency of organic solar cells. Zinc oxide (ZnO) in nanostructured form helps to overcome this problem by introducing a ZnO buffer layer between the photoanode and the donor material. To achieve this, the ZnO thin film must exhibit good crystallinity, along with good electrical conductivity and high optical transparency in the visible range. The aim of this work is to investigate the effect of precursor sources and precursor concentrations on the structural, morphological, and optical properties of ZnO thin films. Three different precursor sources have been used: zinc acetate, zinc chloride and zinc nitrate. In each deposition solution, the precursor concentration varied from 0.1 M to 0.3 M. The ZnO films were deposited on glass substrates and all the films were annealed at 400°C for 3 hours. The structural, morphological and optical properties of deposited films were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectroscopy respectively. XRD results showed that, regardless of the precursor source, all the ZnO films are polycrystalline with a hexagonal wurtzite structure. ZnO films obtained from acetate and nitrate sources crystallize preferentially along (002) and the peak intensity increases as the precursor concentration increases. SEM images showed that all the ZnO films are homogeneous, but films deposited from zinc acetate and zinc nitrate looked more compact and smoother than those obtained with zinc chloride which looked porous. UV-visible spectroscopy results revealed that the films transmittance depends both on precursor source and concentration. ZnO thin films deposited from zinc acetate at 0.3M concentration exhibit the best transmittance of 95% due to their smooth and uniform surfaces. The band gap of ZnO obtained from the zinc acetate precursor decreases with increasing solution concentration. It is found to be 3.29 eV, 3.26 eV, and 3.22 eV for concentrations of 0.1 M, 0.2 M, and 0.3 M, respectively. It therefore appears that ZnO films obtained from zinc acetate can be used as an electron transport layer for solar cells as they exhibit the best crystallinity and the highest transmittance
Effect of a zinc oxide, at the cathode interface, on the efficiency of inverted organic photovoltaic cells based on the CuPc/C60 couple
No full textThe effect of ZnO buffer layer on the performances of inverted multilayers organic solar cells has been studied. ZnO:Al conductive films and insulating ZnO films deposited by spin coating have been probed. The ZnO buffer layer has been introduced between the ITO cathode and the Organic acceptor. The cells are based on the multilayer junctions bathocuproine/fullerene/copper phthalocyanine. The organic photovoltaic cells performances improvement depends of the ZnO layer introduced. ZnO:Al conductive layers decreases the potential barrier at the interface cathode/organic. This allows decreasing the series resistance which improves significantly the cell efficiency. Insulating ZnO increases only slightly the solar cells performance by increasing significantly the shunt resistance and therefore the open circuit voltage of the cells
Contaminantes emergentes en diferentes matrices de aguas y tratamientos alternativos para su eliminación
No full textDurante décadas los contaminantes emergentes (CE) han pasado desapercibido debido a las bajas concentraciones en las que se encuentran en el medio, pero que, en estos últimos años han despertado un gran interés por ser sustancias toxicas que en su mayoría son vertidos al medio acuático, como suele pasar con los plaguicidas, productos de uso personal, metabolitos de fármacos y drogas, entre otros. Por esto se ha hecho necesario desarrollar e implementar nuevas tecnologías para el tratamiento de aguas y eficientes para su eliminación. El siguiente trabajo tuvo como objetivo recopilar información asociada a contaminantes emergentes en agua potable, residual y biota acuática; así mismo, de métodos de tratamiento, degradación y análisis químico, revelando así, información útil para futuras investigaciones en Colombia. Para ello, se realizó una recopilación bibliográfica a través del uso de bases de datos como: Reaxys y Science Direct, con una ventana de observación de cinco años (2015 hasta 2020). Como resultado de esta investigación se obtuvo bases para la orientación de proyectos de investigación, monitoreo, distribución y concentración de las sustancias emergentes.INTRODUCCIÓN ................................................................................................................... 11OBJETIVOS ............................................................................................................................ 14OBJETIVO GENERAL ................................................................................................. 14OBJETIVOS ESPECÍFICOS: ....................................................................................... 14MATERIALES Y METODOS ............................................................................................... 15DESARROLLO DEL TEMA ................................................................................................. 16CAPITULO I: GENERALIDADES DE LOS CONTAMINANTES EMERGENTE ..............16Ejemplo de contaminantes emergentes ..................................................................... 19TIPOS DE CONTAMINANTES EMERGENTES .................................................. 20Fármacos y productos de higiene personal ....................................................... 21Retardantes de llama bromados ........................................................................ 24Surfactantes ......................................................................................................... 25Parafinas cloradas ............................................................................................... 26Productos para el tratamiento de aguas ............................................................ 26Plaguicidas ........................................................................................................... 27Drogas Ilícitas ...................................................................................................... 28PRINCIPALES FUENTES Y RUTAS DE LOS CONTAMINANTES EMERGENTES ........................................................................................................................... 29Fuentes ................................................................................................................. 29Rutas ..................................................................................................................... 30CAPITULO II: NORMATIVA .......................................................................................... 31Regulación y clasificación ........................................................................................... 31Regulación de aguas residuales hospitalarias ........................................................... 33Regulación internacional ............................................................................................ 35ALEMANIA ......................................................................................................... 37FRANCIA ............................................................................................................ 39SUIZA ................................................................................................................... 39ESTADOS UNIDOS ............................................................................................ 40AUSTRALIA ....................................................................................................... 41REGLAMENTACIÓN DE LA LEY DE PROTECCIÓN AMBIENTAL CANADIENSE Y AUSTRALIANA Y EL MINISTERIO DE SALUD DE JAPÓN ............ 43LATINOAMÉRICA .................................................................................................... 43COLOMBIA ............................................................................................................... 45CAPITULO III: CONTAMINATES EMERGENTES EN DIFERENTES MATRICES AMBIENTALES. ............................................................................................................................ 46CONTAMINANTES EMERGENTES EN BIOTA ACUÁTICA ........................... 46Recolección de muestras y pretratamiento ....................................................... 48Extracción ............................................................................................................ 50Muestras líquidas ................................................................................................ 52Muestras sólidas .................................................................................................. 52Limpieza ............................................................................................................... 55Determinación ...................................................................................................... 56CONTAMINANTES EMRERGENTES EN AGUAS RESIDUALES ....................... 59ANÁLISIS DE CONTAMINATES EMERGENTES ................................................ 60Recolección de muestra .............................................................................................. 60Extracción ................................................................................................................... 61Determinación................................................................................................................ 61CONTAMINATES EMERGENTES EN AGUA POTABLE ..................................... 69MÉTODOS DE ANÁLISIS .................................................................................... 70CAPÍTULO IV: CONTAMINATES EMERGENTES EN LATINOAMÉRICA ......... 74Principales contaminantes estudiados ................................................................... 77Contaminantes emergentes en aguas residuales (drenaje urbano) ................. 79Agua potable ........................................................................................................ 81Agua superficial ................................................................................................... 83DISCUSIONES ........................................................................................................................ 91CONCLUSIONES ................................................................................................................... 97REFERENCIAS BIBLIOGRÁFICAS .................................................................................. 99MonografíaPregradoQuímico(a
