0000000000085980
AUTHOR
Ramón Manuel Fernández-domene
Influence of annealing atmosphere on photoelectrochemical response of TiO2 nanotubes anodized under controlled hydrodynamic conditions
[EN] The influence of three annealing atmospheres (air, nitrogen and argon) and the use of controlled hydrodynamic conditions (from 0 to 5000 rpm) on morphological, structural, chemical and photoelectrochemical properties of TiO2 nanotubes have been evaluated. For this purpose, different characterization techniques have been used: Field Emission Scanning Electron Microscopy, Raman Confocal Laser Spectroscopy, X-Ray Diffraction, X-Ray Photoelectron Spectroscopy, Incident Photon-to-electron Conversion Efficiency measurements, ultraviolet-visible absorption spectra, Mott-Schottky analysis and photoelectrochemical water splitting tests. According to the results, it can be concluded that both hy…
Degradation of Diazinon based on photoelectrocatalytic technique using enhanced WO3 nanostructures: Mechanism and pathway
[EN] In this work, a resistant and toxic pesticide called diazinon was degraded through the photoelectrocatalysis (PEC) technique using tungsten oxide (WO3) nanostructures, applying an external bias of 1VAg/AgCl and simulated solar illumination. For this, WO3 nanostructures have been synthesized using electrochemical anodization in 0.05 M hydrogen peroxide and 1.5 M of different acidic electrolytes: H2SO4, CH4O3S or HNO3. Morphology, composition and crystallinity of the samples were evaluated through Field Emission Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM) and Raman Spectroscopy. Then, the photoelectrochemical properties of the samples were analyzed by Photo-Elect…
Organophosphorus pesticides (chlorfenvinphos, phosmet and fenamiphos) photoelectrodegradation by using WO3 nanostructures as photoanode
[EN] The photoelectrocatalytic (PEC) degradation of recalcitrant and toxic organophosphorus pesticides, fenamiphos, chlorfenvinphos and phosmet, has been performed by using an innovative WO3 nanostructure as photoanode. The nanostructure has been synthesized by anodization in acidic media in the presence of a very small amount (0.05 M) of H2O2, and its composition as well as its photoelectrochemical properties have been characterized using X-ray Photoelectron Spectroscopy and X-ray diffraction as composition technique and photoelectrochemical impedance spectroscopy as photoelectrochemical analysis. After 24 h of experiment, a degradation of 95% of chlorfenvinphos, 99.9% of phosmet and 100% …
Original Approach to Synthesize TiO2/ZnO Hybrid Nanosponges Used as Photoanodes for Photoelectrochemical Applications
[EN] In the present work, TiO2/ZnO hybrid nanosponges have been synthesized for the first time. First, TiO2 nanosponges were obtained by anodization under hydrodynamic conditions in a glycerol/water/NH4F electrolyte. Next, in order to achieve the anatase phase of TiO2 and improve its photocatalytic behaviour, the samples were annealed at 450 degrees C for 1 h. Once the TiO2 nanosponges were synthesized, TiO2/ZnO hybrid nanosponges were obtained by electrodeposition of ZnO on TiO2 nanosponges using different temperatures, times, and concentrations of zinc nitrate (Zn(NO3)(2)). TiO2/ZnO hybrid nanosponges were used as photoanodes in photoelectrochemical water splitting tests. The results indi…
Synthesis of WO3 nanorods through anodization in the presence of citric acid: Formation mechanism, properties and photoelectrocatalytic performance
[EN] In this study, WO3 nanomds have been fabricated by simple anodization in the presence of different amounts of citric acid and at different anodization times. A comprehensive morphological, structural, electrochemical and photoelectrochemical characterization of different samples has been carried out. Moreover, a formation mechanism for WO3 nanorods has been proposed. Finally, these nanostructures have been proven to be excellent visible-light photoelectrocatalysts to remove persistent organic pollutants present in wastewaters, such as fenamiphos. Almost the 80% of this molecule was eliminated from the test solution after 180 min of irradiation, indicating the great potential of these W…
Implementación del método del caso en la asignatura de Ingeniería de Procesos y Productos II del grado en Ingeniería Química
[EN] In this work, the case method has been used in the subject Process and Product Engineering II, which belongs to the fourth course of the Chemical Engineering Degree of the Universitat de València. Different cases have been proposed in the classroom practices in order to students acquire the competences of the subject and improve the results of the exam. A rubric was designed to evaluate the cases which was accessible to the students. The cases were proposed in the exam, in particular, cases related to four lessons which are usually complicated to students and the results obtained for these cases were compared with the results obtained in the questions (presented in a theoretical way) o…
ZnO nanostructures: synthesis by anodization and applications in photoelectrocatalysis
Abstract Solar energy is a clean and abundant energy source. In a photoelectrochemical cell, energy from sunlight is captured and converted into electric power, chemical fuels such as hydrogen is employed to degrade organic pollutants. ZnO is a promising material for photoelectrocatalysis due to its remarkable properties. The aim of this review is to perform an exhaustive revision of nanostructured ZnO synthesis by electrochemical anodization in order to control surface characteristics of this material through anodization parameters such as electrolyte type and concentration, potential, time, temperature, stirring, and post treatment. Finally, application of ZnO nanostructures is overviewed…
Control on the morphology and photoelectrocatalytic properties of ZnO nanostructures by simple anodization varying electrolyte composition
Abstract Zinc oxide nanostructured electrodes were successfully synthesized by a simple method of anodization in different aqueous bicarbonate electrolytes. The influence of the anodization electrolyte composition (by adding ethanol or glycerol) on the morphology and the photoelectrocatalytic properties of the zinc oxide electrodes was studied, as well as the combined effect of anodizing under controlled hydrodynamic conditions. Field Emission Scanning Electron Microscope (FE-SEM) images of the ZnO electrodes showed that the addition of ethanol or glycerol to the anodization electrolyte resulted in changes in size and morphology of the nanostructures. Thus, ZnO nanowires, nanotubes, nanospo…
Novel TiO2-WO3 self-ordered nanotubes used as photoanodes: Influence of Na2WO4 and H2O2 concentration during electrodeposition
[EN] Hybrid TiO2-WO3 nanostructures has been synthesized by electrochemical anodization under controlled hydrodynamic conditions followed by electrodeposition in the presence of different contents of Na2WO4 (5, 15 and 25 mM) and H2O2 (20, 30 and 40 mM). The influence of the electrolyte used for electrodeposition on the morphology, crystalline structure and photoelectrochemical response for water splitting has been evaluated through Field Emission Electronic Microscopy, High-Resolution Transmission Electron Microscopy, Confocal Raman Spectroscopy, Grazing Incidence X Ray Diffraction, X-Ray Photoelectron Spectroscopy, Atomic Force microscopy and photocurrent versus potential measurements. Add…