Ceramica constituida por un material inorganico de base dopado por un elemento J, teniendo dicho material inorganico de base un punto de fusion superior a 300oC, estando dicho dopante constituido por un unico material inorganico o por una mezcla de al menos dos materiales inorganicos que tienen un efecto dopante sobre el material inorganico de base, estando dicha ceramica representada por la formula (I) Eα-x'kJx'mOβ-x'(k-m)/22-□x'(k-m)/2 en la que: - EαkOβ2- designa el material inorganico de base; - E designa al menos un metal de los grupos I a VIII de la tabla periodica de los elementos, y k designa el grado de oxidacion medio de E en la formula I; - J representa al menos un metal de los grupos I a VIII de la tabla periodica, y m designa el grado de oxidacion medio del elemento J que esta parcialmente sustituido en E, m es un numero entero positivo tal que m < k; - α, k y β son numeros positivos comprendidos entre 1 y 20, tales que αk - 2β = 0; - x' designa la tasa de sustitucion y es un numero positivo tal que x' < α; - □ representa una vacante anionica; estando dicha ceramica caracterizada por una estructura cristalina de tipo bixbyita y porque el material inorganico de base es In2O3, presentando la ceramica una conductividad superior al 70% de la conductividad teorica, y porque comprende porcentajes molares de SnO2 y ZnO comprendidos cada uno entre el 3 y el 15%, con un porcentaje de ZnO superior o igual al de SnO2, estando dicha ceramica caracterizada porque presenta al menos una de las siguientes propiedades: i) una conductividad electrica macroscopica, medida segun el metodo de las cuatro puntas ("Four Probe measurements") con un aparato Keithley (modelo 2400 Source Meter), que es superior a 300 siemens por cm; ii) una densidad aparente mejorada, medida segun el metodo del porosimetro de mercurio, comprendida entre 6 y 7,1 g/cm3; iii) una superficie (total) superior a 5 cm2; iv) un porcentaje mejorado de irregularidades de juntas de granos, medido segun el metodo de microscopio electronico de alta resolucion que es inferior al 30% del de una ceramica correspondiente preparada sin adicion de elemento dopante mediante el metodo convencional; y v) un tamano de los poros presentes en la ceramica, medido mediante el metodo del MEB de alta resolucion, que esta comprendido entre 0,1 y 0,8 micrometros.

For the first time, pristine ZnO nano-particles can be used as effective catalyst for water disinfection by killing and complete mineralization of two gram negative bacteria with direct solar light. Just like in earlier studies, pristine nano-size ZnO particles have shown anti-bacterial activity against two types of gram negative bacteria, E. coli and P. aeruginosa, where up to 20% of the former and 25% of the latter have been killed in the dark. Under direct solar radiation, the pristine ZnO particles readily catalyzed bacterial photo-degradation. While earlier studies were mostly limited to bacterial death and growth inhibition by pristine ZnO particles, the results describe for the first time how bacteria and their organic content can be completely photo-mineralized by direct solar radiations in 60 min. Only the bacterial cell wall fragments resisted the photo-degradation process. Under the reaction conditions, the degradation occurred by the UV tail of the direct solar light, where the ZnO nano particles behaved as photo-catalysts. The results show the added value of using ZnO nano-particles as photo catalysts in water disinfection strategies, leaving no resulting organic molecules in water.

Polycrystalline CdSe films have been deposited onto fluorine doped tin oxide (FTO/glass) substrates by three different techniques, electrochemical deposition (ECD), chemical bath deposition (CBD) and, for the first time, combined ECD and CBD (ECD/CBD). The films were comparatively characterized by photoluminescence spectra (PL), electronic absorption spectra, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The SEM micrographs show that the films involved rod shaped agglomerates with various lengths and widths. XRD patterns show that the three systems involved nano-sized CdSe particles with cubic type crystals. Based on Scherrer's equation, the ECD film showed larger particle size than the CBD film, while the ECD/CBD film showed largest particles among the series. Similarly, the band gap values varied for different films as CBD>ECD>ECD/CBD. Photo-electrochemical (PEC) characteristics, including photo-current density vs. voltage (J-V) plots, conversion efficiency (ƞ), fill factor (FF) and stability were all studied for different film electrodes. The films exhibited n-type behaviors with direct band gaps. The new ECD/CBD-CdSe electrode exhibited higher conversion efficiency (ƞ% ~4.40) than other counterparts. The results show the added value of combining ECD and CBD methods in enhancing PEC characteristics of CdSe film electrodes, even with no additional treatment.

This communication describes for the first time how nano-size particles, sensitized with natural dye molecules of anthocyanin, can be used as catalysts in photo-degradation of gram negative Escherichia coli bacteria in water. The naked ZnO nano-particles degraded up to 83% of the bacteria under solar simulator light, while the dye-sensitized particles increased the bacterial loss by similar to 10%. Solar simulator light includes about 5% of UV tail (shorter than 400 nm) which means that both UV and visible light (longer than 400 nm) radiations could be involved. When a cut-off filter was used, the naked ZnO caused only 40% bacterial loss, in accordance with earlier literature that described killing of bacteria with ZnO particles both in the dark and under light. With the cut-off filter, the sensitized ZnO particles caused higher than 90% bacterial loss, which confirms sensitization of the ZnO particles to visible light. Moreover, the results show that the catalyzed photo-degradation process causes mineralization of the bacteria and their organic internal components which leach out by killing. The catalyst can be recovered and reused losing similar to 10% of its activity each time due to mineralization of the dye molecules. However, catalyst activity can be totally regained by re-sensitizing it with the anthocyanin dye. The effects of different experimental conditions, such as reaction temperature, pH, bacterial concentration and catalyst amount together with nutrient broth and saline media, will be discussed together with the role of the sensitizer. (C) 2016 Elsevier B.V. All rights reserved.

Photo-degradation of organic contaminants into non-hazardous mineral compounds is emerging as a strategy to purify water and environment. Tremendous research is being done using direct solar light for these purposes. In this paper we report on optimum conditions for complete mineralization of aqueous methyl orange using lab-prepared ZnO nanopowder catalyst under simulated solar light.

Electrodeposited CuSe film electrodes have been prepared onto FTO/glass by a facile method based on earlier methods described for other systems. The films were characterized, modified by annealing and further characterized. The films were then modified by coating with tetra(-4-pyridyl) pophyrinato-manganese (MnTPyP) complexes embedded inside commercial polyethylene (PE) matrices. The effects of modifications on different film properties, such as X-ray diffraction (XRD) patterns, surface morphology, photoluminescence (PL) spectra and electronic absorption spectra were investigated. Compared with other thin film electrode systems, very high photoelectrochemical (PEC) conversion efficiency values have been observed here. Pre-annealing the CuSe films at 150 degrees C for 2 h, followed by attaching the MnTPyP/PE matrices remarkably enhanced their PEC characteristics. The conversion efficiency was significantly enhanced, from less than 1.0% to more than 15%. Fill factor (FF) was also enhanced from similar to 30% to similar to 80%. Values of open-circuit potential (V-OC) and short-circuit current (J(SC)) were significantly enhanced. While annealing affects uniformity, particle inter-connection and surface texture of the CuSe films, the MnTPyP complex species behaves as an additional charge-transfer mediator across the film/electrolyte junction. Optimization of PEC characteristics, using different deposition times, different annealing temperatures, different annealing times and different redox couples, was also investigated. (C) 2015 Elsevier Ltd. All rights reserved.

High conversion efficiency (η) values have been obtained from modified CuS film electrodes electrochemically deposited onto Glass/FTO. The modification involved pre-annealing the film followed by coating with tetra(-4-pyridyl)porphyrinato manganese (MnTPyP+) ions embedded inside a polyethylene (PE) matrix. The Glass/FTO/CuS/MnTPyP/PE electrodes exhibited enhanced photo-electrochemical (PEC) characteristics under solar simulated illumination (5.6mW/cm−2) in aqueous media, compared to the as-prepared Glass/FTO/CuS films which showed no PEC activity. Up to 17.4% efficiency and 85% fill factor (FF) values were obtained from the modified film electrodes. Such characteristics have not been widely known for metal chalcogenide based film electrodes before. Different pre-annealing temperatures were attempted and the 250°C temperature, followed by quenching, showed favorable results. Different aqueous redox couples were studied and the environmentally safe FeCl2/FeCl3 aqueous system showed highest PEC characteristics. Effect of pre-annealing on film electrode characteristics is discussed. The MnTPyP/PE matrix behaves as charge transfer catalyst for the holes across the CuS film/liquid junction.

Successful preparation of tungsten oxide thin films on paper substrate, using a novel room temperature deposition method involving the connection of tungsten oxide nanoparticles by UV-irradiation, is reported. WO3 thin films, prepared from synthesized monoclinic WO3 powder as compared to commercial ones, show higher electrochemical activity and good cycling stability in 0.3 M trifluoromethanesulfonimide (HTFSI) in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMITFSI) ionic liquid electrolyte versus Pt as counter electrode. Electrochromic performances of complete devices using Prussian Blue (PB) as complementary counter electrode and 0.3 M Lithium Bis(Trifluoromethanesulfonyl)Imide LiTFSI in BMITFSI plastified with polymethylmetacrylate (PMMA) membrane electrolyte are associated with a contrast in reflectance of 13%, from a yellow to a blue color. (C) 2014 Elsevier Ltd. All rights reserved.

A facile and low-cost strategy to improve stability and conversion efficiency of CdSe film electrodes prepared by chemical bath deposition (CBD) onto FTO/glass substrates, is described. The naked CdSe film electrodes, with band gap value 1.8 eV, photo-corroded under the photoelectrochemical (PEC) working conditions and exhibited no photocurrent. The CdSe film peeled out in short times. Attempts made to enhance stability and efficiency of naked CdSe electrodes, by chemical etching or pre-scratching the FTO surface with fine sand-paper, failed to improve film PEC characteristics. Annealing the glass/FTO/CdSe film also failed to improve its PEC stability or efficiency. When coated with the electro-active species Tetra(-4-pyridyl)porphyrinatomanganese(III/II) sulfate embedded inside polysiloxane films (MnPyP/Polysil) the CdSe films did not peel out under the PEC conditions. The coated electrode (glass/FTO/CdSe/MnPyP/Polysil) clearly exhibited photocurrents. Pre-annealing the naked CdSe film at 350 degrees C, followed by coating with MnPyP/Polysil further enhanced the electrode PEC characteristics. Additional heating of the prepared glass/FTO/CdSe/MnPyP/Polysil electrode at 120 degrees C also enhanced its PEC characteristics. The mode of action of the MnPyP/Polysil coating has been attributed to its ability to behave as a charge transfer catalyst at the solid/liquid interface. The new technique described here could also be potentially valuable for other types of thin film electrode materials. (C) 2014 Elsevier Ltd. All rights reserved.

Electrochromic nickel oxide (Ni1 - xO) pigment powder which was made from nickel acetate reacting with H2O2/urea solution followed by heat treatment of xerogels at 400 degrees C (24 h) was milled with zirconia beads in pure water or water with added nickel oxyhydroxy precipitate acting simultaneously as the dispersant and the coating binder. The corresponding pigment particle suspensions were spin coated on FTO glass and flexible ITO-PET foils, respectively, and cured at 150 degrees C. The optical properties of the deposited pigment coatings on FTO glass substrates were determined with an UV VIS spectrometer, providing total direct transmittance (TT), total diffuse transmittance (DT) and haze (in %). Haze increased with the coating thickness but did not exceed 4%. SEM micrographs of the deposited pigment coatings revealed that they consisted of agglomerated Ni-1 O- x pigment with voids.Potential cycling of Ni1 - xO pigment coatings and Ni1 - xO thin films was performed in 1 M LiClO4/PC and 0.1 M TBA(+) triflate/PC electrolytes, revealing that the pigment coatings exhibited electrochemical and electrochromic activity also in lithium free (aprotic) electrolyte, while variations of the oxidation and reduction reaction peaks at various scan rates confirmed the presence of surface electrochemical reactions. The near-grazing incidence angle reflection-absorption spectroscopic technique (IR RA) was employed for identifying surface and inner-grain Ni-O stretching modes, the former being responsible for observed electrochemical properties, which was also demonstrated from the ex situ IR RA measurements performed for coatings charged/discharged in 1 M LiClO4/PC and 0.1 M TBA+ triflate/PC electrolytes. The results disclosed in this study suggest that the electrochromic effect was not in direct correlation with the de-insertion/insertion of small ions into the NiO (bunsenite) grains but rather the pigment coatings behave similarly to nickel oxide electrochemical capacitors. The electrochromic response of a flexible EC devices made either of PEDOT (self-standing foil) or WO3 and Ni1 - xO pigment coatings glued with PMMA based electrolytes without and with lithium salt were recorded for the demonstration of the possible practical application of wet deposited Ni1- xO pigment coatings made as "electrochromic paints. (C) 2013 Elsevier B.V. All rights reserved.

Electrochromic (EC) performances of Ni3+ containing NiO thin films, called modified NiO thin films, prepared either by pulsed laser deposition or by chemical route are reported. When cycled in lithium based electrolyte, the comparison of the EC behavior of nonstoichiometric NiO thin films points out a larger optical contrast for the films synthesized by chemical route with the absence of an activation period on early electrochemical cycling due in particular to a larger porosity. Herein we demonstrate faster kinetics for modified NiO thin films cycled in lithium ion free electrolyte. Finally, X-ray absorption spectroscopy is used for a preliminary understanding of the mechanism involved in this original EC behavior linked to the film characteristics including their disorder character, the presence of Ni3+ and their porous morphology.

A new method to prepare CdS film electrodes, based on electrochemical deposition (ECD), followed by chemical bath deposition (CBD), is described. The ECD/CBD-CdS film electrodes combine the advantages of both ECD-CdS film (good adherence to FTO/glass substrate) and CBD-CdS film (suitable film thickness) together. The new ECD/CBD electrode showed higher photo-electrochemical (PEC) efficiency and stability than either ECD- or CBD-CdS film electrodes, especially after annealing. Inter-particle connection and uniformity of the ECD/CBD-CdS film were further enhanced by annealing. Consequently, the electrode PEC conversion efficiency and stability were enhanced. The combined preparation technique, followed by annealing, is potentially useful for future manufacturing of CdS and other film electrode systems. (C) 2013 Elsevier B.V. All rights reserved.

CdS thin films have been deposited onto FTO/glass substrates by two different techniques, electrochemical deposition (ECD) and chemical bath deposition (CBD). Feasibility of using these two film types in photoelectrochemical processes has been critically investigated here. The films were comparatively characterized by a number of techniques (solid state absorption spectra, solid state photoluminescence spectra, XRD and SEM). PEC characteristics of the electrodes, including current density–voltage (J–V) plots, conversion efficiency (η), stability and fill-factor (FF) were then studied. The results show that both systems involved nano-sized CdS particles living in coagulates. The ECD was thinner and more uniform than the CBD system. The CBD films were more effective in PEC processes than the ECD counterparts. Effect of annealing on characteristics of both electrode systems has been investigated. Annealing enhanced both film characteristics, but the CBD was affected to a higher extent, and the annealed CBD film was more effective than the ECD counterpart.

Indium oxide co-doped with tin and zinc (ITZO) ceramics have been successfully prepared by direct sintering of the powders mixture at 1300 degrees C. This allowed us to easily fabricate large highly dense target suitable for sputtering transparent conducting oxide (TCO) films, without using any cold or hot pressing techniques. Hence, the optimized ITZO ceramic reaches a high relative bulk density (similar to 92% of In2O3 theoretical density) and higher than the well-known indium oxide doped with tin (ITO) prepared under similar conditions. All X-ray diagrams obtained for ITZO ceramics confirms a bixbyte structure typical for In2O3 only. This indicates a higher solubility limit of Sn and Zn when they are co-doped into In2O3 forming a solid-solution. A very low value of electrical resistivity is obtained for [In2O3:Sn-0.10]:Zn-0.10 (1.7 x 10(-3) Omega cm, lower than ITO counterpart) which could be fabricated to high dense ceramic target suing pressure-less sintering. (C) 2012 Elsevier Masson SAS. All rights reserved.

Aiming at enhancing the electrochromic properties of anodically colored NiO thin films, lithium doped NiO thin films were grown on FTO/glass substrates, by the pulsed laser deposition (PLD) method. Optimized conditions, namely a room temperature substrate under 10 Pa oxygen pressure were used. Comparison with undoped NiO thin films indicates that lithium doping deteriorates NiO cubic phase (1 1 1) preferred orientation and also induces lattice disorder. The investigation of the electrochromic properties of Li–Ni–O thin films in aqueous liquid electrolyte, 1 M KOH, on the one hand and in hydrophobic lithium conductive ionic liquid, 0.3 M LiTFSI in BMITFSI, on the other hand, demonstrates an improvement in the electrochromic performances with lithium doping. Finally, electrochromic devices built on the association of WO3 and Li–Ni–O thin films and using the above quoted ionic liquid blended with PMMA as electrolyte are reported. Good electrochromic performances and neutral color are shown.

Silicon doped Zinc Oxide thin films, so-called SZO, were deposited at room temperature on glass and plastic substrates by co-sputtering of ZnO and SiO2 targets. The influence of the SiO2 target power supply (from 30 to 75W) on the SZO thin film composition and crystallinity is discussed. Si/Zn atomic ratio, determined by X-ray microprobe, increases from 1.2 to 8.2at.%. For Si/Zn ratio equal and lower than 3.9%, SZO (S3.9ZO) thin films exhibit the Wurzite structure with the (0 0 2) preferred orientation. Larger Si content leads to a decrease in crystallinity. With Si addition, the resistivity decreases down to 3.5×10−3Ω·cm for SZO thin film containing 3.9at.% of Si prior to an increase. The mean transmittance of S3.9ZO thin film on glass substrate approaches 80% (it is about 90% for the film itself) in the visible range (from 400 to 750nm). Co-sputtered SZO thin films are suitable candidates for large area transparent conductive oxides.

Doped zinc oxide thin films are grown on glass substrate at room temperature under oxygen atmosphere, using pulsed laser deposition (PLD). O-2 pressure below 1 Pa leads to conductive films. A careful characterization of the film stoichiometry and microstructure using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) concludes on a decrease in crystallinity with Al and Ga additions (<= 3%). The progressive loss of the (0 0 2) orientation is associated with a variation of the c parameter value as a function of the film thickness and substrate nature. ZnO:Al and ZnO:Ga thin films show a high optical transmittance (> 80%) with an increase in band gap from 3.27 eV (pure ZnO) to 3.88 eV and 3.61 eV for Al and Ga doping, respectively. Optical carrier concentration, optical mobility and optical resistivity are deduced from simulation of the optical data. (C) 2010 Elsevier B. V. All rights reserved.

Si doped zinc oxide (SZO, Si 3%) thin films are grown at low substrate temperature (T≤150°C) under oxygen atmosphere, using pulsed laser deposition (PLD). Si addition leads to film amorphization and higher densification. Hall effect measurements indicate a resistivity of 7.9×10−4Ωcm for SZO thin films deposited at 100°C under optimized 1.0Pa oxygen pressure. This value is in good agreement with optical resistivity simulated from the transmittance spectra. XPS measurements suggest more than one oxygen environment, and a Si oxidation state lying in between 2 and 3 only. As a matter of fact, the values of both measured and simulated carrier numbers are smaller than the ones expected, assuming that all Si cations in the ZnO matrix are at the 4+ oxidation state. Finally, the differences in the electrical and optical properties of SZO thin films deposited both on glass and PET substrates confirm the strong dependency of the electronic properties to the film crystallinity and stoichiometry in relationship with the substrate nature.