Teresa Lana-Villarreal

• University of Alicante

Recent years have witnessed an intense effort to unravel magnetic field effects in electrocatalysis, as they can enhance the performance of common electrocatalysts. Both experimental and theoretical studies have shown that magnetic fields may affect, among others, the macroscopic spin‐orbital ordering, charge transport, bubble release, and electron...

Rechargeable magnesium batteries are an attractive alternative to lithium batteries because of their higher safety and lower cost, being spinel-type materials promising candidates for their positive electrode. Herein, MgMn2O4 with a tetragonal structure is synthesized via a simple, low-cost Pechini methodology and tested in aqueous media. Electroch...

Oxide photoelectrochemistry has been under continuous development over the last half century. These decades have witnessed the use of electrodes of different nature (from single crystals to nanoparticulate films), new electrode materials (including ternary and multinary transition metal oxides), and different strategies for improving their efficien...

NiFe- and CoFe-based (oxy)hydroxides stand out as promising and highly active earth-abundant electrocatalysts for the oxygen evolution reaction (OER) in alkaline media. Fe(OH)2-Ni(OH)2 and Fe(OH)2-Co(OH)2 electrodes have been prepared through a urea-based chemical bath deposition (CBD) method that enables to control and optimize structure and loadi...

A number of metal oxides have been proposed as useful materials for the photoelectrochemical (PEC) production of hydrogen from water. However, up to now, an ideal standalone material has not been found. We have investigated the possible use of nickel titanate (NiTiO3) nanorods as a photoanode. Although these electrodes absorb visible light, they sh...

Introducing molecular dopants in carbon nitride has been shown to dramatically modify its electronic structure, resulting in efficient charge separation and improved photocatalytic efficiency. Herein, we have studied the effect of doping carbon nitride with 2-aminothiophene-3-carbonitrile. A fundamental photoelectrochemical characterization has bee...

Studies on water-splitting p-type oxide electrodes based on nontoxic earth-abundant elements are scarce. Herein, the behavior of electrodes composed of CuFe2 O4 nanoparticles 30 nm in size is presented. The as-prepared CuFe2 O4 nanoporous electrodes exhibit small anodic photocurrents in 0.1 m NaOH. However, an electrochemical pretreatment consistin...

High intensity ultrasound can be used for the production of novel nanomaterials, including metal oxides. According to previous works in this field, the most notable effects are consequence of acoustic cavitation. In this context, we have studied the preparation of different materials in the presence of ultrasound, including N-doped TiO2 nanopowder,...

Ilmenite type titanates have very wide applications in various fields. In this paper, we report the synthesis of mesoporous NiTiO3 ilmenite nanorods via a sonochemical approach. The method is very facile and effective allowing to prepare NiTiO3 nanoparticles with a high yield and uniform size distribution. The reaction intermediate and particularly...

The selective hydrogenation of 2-methyl-3-butyn-2-ol (MBY) was performed in the presence of Lindlar catalyst, comparing conventional stirring with sonication at different frequencies of 40, 380 and 850kHz. Under conventional stirring, the reaction rates were limited by intrinsic kinetics, while in the case of sonication, the reaction rates were 50-...

Two new hybrid molybdenum(IV) Mo3S7 cluster complexes derivatized with diimino ligands have been prepared by replacement of the two bromine atoms of [Mo3S7Br6]2− by a substituted bipyridine ligand to afford heteroleptic molybdenum(IV) Mo3S7Br4(diimino) complexes. Adsorption of the Mo3S7 cores from sample solutions on TiO2 was only achieved from the...

The electronic properties of hematite were investigated by means of synchrotron radiation photoemission (SR-PES) and X-ray absorption spectroscopy (XAS). Hematite samples were exposed to trimethyl aluminum (TMA) pulses, a widely used Al-precursor for the atomic layer deposition (ALD) of Al2O3. SR-PES and XAS showed that the electronic properties of...

We quantify the rate and efficiency of picosecond electron transfer (ET) from PbS nanocrystals, grown by successive ionic layer adsorption and reaction (SILAR), into a mesoporous SnO2 support. Successive SILAR deposition steps allow for stoichiometry- and size-variation of the QDs, characterized using transmission electron microscopy. Whereas for s...

In the field of energy saving, finding composite materials with the ability of coloring upon both illumination and change of the applied electrode potential keeps on being an important goal. In this context, chemical bath deposition of Ni(OH)2 into nanoporous TiO2 thin films supported on conducting glass leads to electrodes showing both conventiona...

The concept of interfacial polymerization is utilized for the synthesis of polyaniline–phospho-molybdate (PAni–PMo12) molecular hybrids and it is well characterized. The electrical conductivity of the synthesized hybrid materials increases with increase in PMo12 wt%. The synthesized hybrid materials are evaluated as the active electrode materials f...

Heavy metal-based quantum dots (QDs) have been demonstrated to behave as efficient sensitizers in QD-sensitized solar cells (QDSSCs), as attested by the countless studies and encouraging efficiencies reported so far. However, their intrinsic toxicity has arisen as a major issue for the prospects of commercialization. Here, we examine the potential...

Among the third-generation solar cells based on quantum dots, the quantum dot-sensitized solar cells (QDSSCs) have received substantial attention probably because they are a straightforward extension of the very popular dye-sensitized solar cells. The nature of the quantum dots (QDs) and their mode of attachment to a wide band gap semiconductor (ox...

Nanostructured Copper Ferrite as Photocathode for Water Photoreduction

Quantum dot sensitized solar cells (QDSCs) are receiving a lot of attention as promising third generation solar cells, being virtually all of them based on sensitized photoanodes. Finding efficient QD-sensitized photocathodes would pave the way toward the implementation of tandem QDSCs. In this context, NiO photocathodes have been sensitized with c...

Ultrathin and transparent nanostructured Ni(OH)2 films were deposited on conducting glass (F:SnO2) by a urea-based chemical bath deposition method. By controlling the deposition time, the amount of deposited Ni(OH)2 was varied over 7 orders of magnitude. The turnover number for O2 generation, defined as the number of O2 molecules generated per cata...

TiO2 nanotubes (NTs) have been widely used for a number of applications including solar cells, photo(electro)chromic devices, and photocatalysis. Their quasi-one-dimensional morphology has the advantage of a fast electron transport although they have a relatively reduced interfacial area compared with nanoparticulate films. In this study, verticall...

The use of PbSe quantum dots (QDs) as sensitizers for TiO2 samples has been primarily hampered by limitations on charge injection. Herein, a novel successive ionic layer adsorption and reaction (SILAR) method, allowing for an intimate TiO2/PbSe contact and a strong quantum confinement, is described. Photoelectrochemical experiments and transient ab...

Good relations: The electron lifetime (τ) has turned out to be one of the most influential parameters in the performance of quantum-dot- and dye-sensitized solar cells. Different approaches for the analysis of the open-circuit-potential decay are presented, showing the strong effect on the calculated lifetime values of the way of relating potential...

European Higher Education Area (EHEA) has set off a deep modification of university degrees, regarding not only the curricula and content structure but also their learning approach. A great change has arisen in the teaching-learning model, drifting from a model focused on knowledge acquisition to a model focused on competences. This modification im...

Physical Chemistry is a classic discipline in Chemistry, Chemical Engineering and Pharmacy curricula; its structure is based on many different knowledge areas, which may lead to an inappropriate, disperse and poor study of its contents. The introduction of the European Higher Education Area (EHEA) has triggered a deep review of the Physical Chemist...

The presence of electronic traps in nanoporous TiO(2) electrodes has been studied by cyclic voltammetry in aqueous media. These simple measurements allow us to map the density of states, providing evidence for the presence of a relatively small number of discrete electron traps at the band gap. We have taken advantage of the variety of TiO(2) synth...

Several of the multiple applications of titanium dioxide nanomaterials are directly related to the introduction or generation of charge carriers in the oxide. Thus, electrochemistry plays a central role in the understanding of the factors that must be controlled for the optimization of the material for each application. Herein, the main conceptual...

An oxidative stripping treatment triggers the transition from n- to p-type photoelectrochemical behavior of zinc copper indium sulfide quantum dot electrodes. These electrodes in contact with a polysulfide solution change from photoanodic to photocathodic behavior in a certain potential range upon electrochemical treatment.

Photovoltaic devices comprising metal chalcogenide nanocrystals as light-harvesting components are emerging as a promising power-generation technology. Here, we report a strategy to evenly deposit Sb2Se3 nanoparticles on mesoporous TiO2 as confirmed by Raman spectroscopy, energy-dispersive X-ray spectrometry, and transmission electron microscopy. D...

A hybrid quantum dot sensitized solar cell (QDSC) composed of CdSe quantum dots (QDs) as light harvesters and TiO(2) and 3,3'''-didodecyl-quaterthiophene (QT12) as electron and hole conductors, respectively, has been fully processed in air. The sensitizer has been introduced into the TiO(2) nanoporous layer either by the successive ionic layer adso...

Titanium dioxide is a widely used photocatalyst whose properties can be modified by fluoride adsorption. This work is focused on the effect of surface fluorination on the electrochemical and photoelectrocatalytic properties of TiO(2) nanoporous thin films. Surface fluorination was achieved by simple addition of HF to the working solution (pH 3.5)....

Hybrid structures of colloidal quantum dots (QDs) with Ru-dyes have been studied as candidates for panchromatic sensitizers for TiO2-based solar cells. Steady-state and time resolved photoluminescence spectroscopy and photocurrent measurements have been employed to identify the prevailing transfer mechanisms for photogenerated excitons between CdSe...

Among the third-generation photovoltaic devices, much attention is being paid to the so-called Quantum Dot sensitized Solar Cells (QDSCs). The currently poor performance of QDSCs seems to be efficiently patched by the ZnS treatment, increasing the output parameters of the devices, albeit its function remains rather unclear. Here new insights into t...

Hybrid quantum-dot-sensitized solar cells show promising novel optoelectronic properties. An adequate design of such cells requires a deep understanding of the characteristics of each component, including their interactions. In this context, the electrochemical properties of two different hole-transporting materials (HTMs) and their chemical intera...

Quantum Dot Sensitized Solar Cells are emerging as a new type of photovoltaic device. In this context, ZnO nanoporous films have been sensitized to the visible by depositing CdSe quantum dots (QDs) by the so-called Successive Ionic Layer Adsorption and Reaction (SILAR) method. Experiments using a ZnO(0001) single crystal reveal that the surface is...

Solid-state electropolymerization could be a way to produce organic semiconductors with potential application as Hole Transporting Materials (HTMs) in hybrid organic-inorganic devices. Thereby, thin solid films of triphenylamine (TPA) deposited by spin coating on conducting glass substrates have been electrochemically treated by performing multiple...

The dependence on chemical and electrochemical variables of lead dioxide electrodeposition on a glassy carbon electrode from Pb(II) aqueous solutions has been studied. Depending on the experimental conditions, the mechanism of lead dioxide electrodeposition may involve kinetic or mass transport control. Both modeling and morphological studies of th...

The performance of quantum dot (QD) sensitized solar cells depends mainly on both electron injection from the QDs to the oxide matrix and recombination rates. Here we show a direct correlation between ultrafast carrier dynamics and photoanode (and complete solar cell) performance. TiO 2 nanoparticulate electrodes sensitized with colloidal CdSe QDs...

Quantum dot sensitized solar cells have the potentiality to emerge as viable third-generation photovoltaic devices. In these cells, the photoanode is constituted by a nanostructured oxide layer sensitized to the visible by suitable quantum dots (QDs). Here, we report on some aspects of the sensitization of titanium dioxide nanoparticulate electrode...

Semiconductor quantum dots (QDs) are important candidates as light absorbing materials in low cost and high efficiency sensitized solar cells (SCs). We present a combination of structural, chemical, electrical, and optical characterization that provides insight to the photovoltaic efficiencies of devices formed by TiO ₂ electron conducti...

Titanium dioxide nanotube electrodes were fabricated by anodization of titanium and decorated with quantum-sized rutile nanowires (2nm in diameter) by chemical bath deposition. The length of the nanotubes (120nm in external diameter) was varied between 4 and 10μm by changing the anodization time. The hierarchically organized electrodes present good...

The photoelectrochemical behaviour of anatase thin films with different nanoarchitectures and the same active surface area (or thickness) has been studied in acidic media in the absence and in the presence of formic acid. The electrodes were composed of either wire-like nanocrystal aggregates or commercial TiO(2) nanoparticles. Cyclic voltammetry i...

Solar cells based on a mesoporous structure of TiO2 and the polysulfide redox electrolyte were prepared by direct adsorption of colloidal CdSe quantum dot light absorbers onto the oxide without any particular linker. Several factors cooperate to improve the performance of quantum-dot-sensitized solar cells: an open structure of the wide bandgap ele...

The application of ultrasound to a solution in contact with a semiconductor working electrode leads to a change in its open circuit potential, that is, to the appearance of a sonopotential sensitive to both ultrasonic power and solution composition.

We have investigated the sensitization of nanoporous titanium dioxide by previously synthesized CdSe quantum dots (QDs) protected with trioctylphosphine. Covering the nanoporous TiO 2 films with QDs has been achieved using two strategies: (i) direct adsorption from dichoromethane dispersions and (ii) anchoring the QDs through a molecular linker, co...

We evaluate the applicability of silicon prisms to infrared (IR) spectroscopic investigations of the oxide/electrolyte interface in the attenuated total reflection (ATR) configuration. Using formic acid as a probe adsorbate, a comparison is done between a rutile nanowire film supported on Si and a rutile nanorod film supported on ZnSe. The nanowire...

Transparent electrodes, formed by 50 nm bundles of rutile nanowires (NW), 2 nm in diameter, have been prepared directly by chemical bath deposition at low temperature on conducting glass. The photoelectrocatalytic behavior of such NW electrodes has been studied in acidic solutions in the presence of model organic molecules (formic acid and methanol...

The different processes involved in heterogeneous photocatalysis are affected by both volume and surface properties of the photocatalyst particles. Such properties can be altered through doping or surface modification. A systematic study of these methods is an appropriate way toward the improvement of the photocatalyst efficiency. We will present a...

TiO2 particles were modified with the chalcogenide (Ru xSey) cluster-like nanoparticles. For both TiO2 suspensions and layers containing RuxSey an enhancement of the photogenerated electron consumption via oxygen reduction was observed. The chalcogenide nanoparticles in colloidal form were able to accumulate electrons photogenerated under UV illumi...

Resumen del tema 10. Se presentan diversas reglas y consejos de diseño para mitigar la corrosión. Se explican los métodos de lucha contra la corrosión más usados.

Se discuten los tipos de corrosión más frecuentes en la industria química. Se proponen materiales adecuados para entrar en contacto con las principales disoluciones corrosivas. Se presentan métodos adicionales de protección contra la corrosión, como la protección anódica o los inhibidores.

We performed a spectro-and photoelectrochemical study of electrodes consisting of oriented rutile TiO 2 nanowires with a diameter of $2 nm prepared directly by chemical bath deposition on conducting glass. A significant increase (around 0.25 eV with respect to bulk rutile) of the band gap energy for the nanowire film is observed and attributed to q...

The interaction and photoreactivity of catechol with both anatase and WO3 nanoparticulate samples have been investigated by applying different experimental techniques. Infrared and Raman spectroscopies have been combined to study catechol adsorption from acidic aqueous solutions. Adsorbed (chelating) catecholate is detected on both oxides together...

The photoelectrochemical behaviour of p-Si(100) single crystal electrodes in aqueous solution, covered with a very thin nitride film, was studied. The silicon surface nitridation was achieved in a N2-H2 plasma at floating potential. The as-grown insulating Si3N4 layers, with thickness inferior to 3.1 nm, allow the electrons to tunnel in the presenc...

For monocrystalline TiO 2 electrodes, capacitive currents are observed at potentials that are negative enough to induce the filling of conduction band states. Nanoparticulate electrodes exhibit, apart from these currents, an additional pair of capacitive peaks at more positive potentials, which can be attributed to charge traps in the band gap. We...

Zinc stannate (Zn2SnO4) particles with 27-nm size were synthesized by hydrothermal treatment. Nanoporous Zn2SnO4 thin films were prepared on conducting glass substrates and used as working electrodes in dye-sensitized solar cells, DSSC. Their behavior was compared with standard TiO2 cells, using (TBA)2-cis-Ru(Hdcbpy)2(NCS)2 (known as N719) as a dye...

The scanning microscope for semiconductor characterization, a scanning laser-spot technique, has been used to obtain laterally resolved open circuit photopotential measurements of anatase nanostructured electrodes in contact with acidic solutions of catechol (or salicylic acid). The oxide nanoporous films were supported on a conducting glass plate...

Nanostructured TiO 2 films can be reversibly doped by applying a potential of À0.6 V Ag/AgCl in aqueous 0.1 M HClO 4 for several min-utes. This charge transfer reductive doping causes significant changes of the cyclic voltammograms in the dark. Furthermore, an up to 6-fold increase of the efficiency for water photooxidation is observed upon electro...

The competition of electron transport through the interconnected particle network with charge carrier recombination constitutes a crucial point concerning the applicability of nanostructured electrodes to photoelectrocatalytic devices. Recombination can occur both in the bulk of the nanoparticles as well as at the solid-electrolyte interface. Furth...

The use of the Raman spectroscopy as a technique providing microscopic (vibrational) information on organic adsorbates at the semiconductor/solution interface is illustrated. First, a way of extending surface enhanced Raman spectroscopy to nanostructured thin films of anatase is presented and validated with experiments of phthalic acid adsorption....

We have studied the photoelectrochemical behavior of nanostructured anatase electrodes modified with gold nanoparticles stabilized either with citrate (Aucit) or with tetraoctylammonium bromide (AuTOAB). An increase both in photocurrent and in photopotential was observed in 0.05M NaOH upon modification with AuTOAB. This behavior is attributed to an...

In oxygen-saturated 0.05 M NaOH, anatase nanoporous electrodes modified with gold nanoparticles show, under Xe arc-lamp illumination, cathodic photocurrents at E < -0-35 V-Ag/AgCl in addition to the typical anodic photocurrents due to water photooxidation at higher potentials. These cathodic photocurrents are suppressed either in the absence of dis...

We have combined in situ photoelectrochemical and spectroscopic techniques (Attenuated Total Reflection Infrared, ATR-IR, and Resonance Raman Spectroscopy) for the study of the charge-transfer complex formed upon adsorption of catechol on anatase nanoparticles in contact with aqueous acidic solutions. Vibrational spectroscopies reveal the existence...

Nanostructured TiO(2) thin-film electrodes of controlled thickness were obtained by immobilization of TiO(2) powder (Degussa P25) on SnO(2):F (FTO)-coated glasses by electrophoresis. The photocurrent-potential characteristics of the electrodes in contact with an indifferent aqueous electrolyte, for both front--and backside UV illumination, show the...

A model for describing the photoelectrochemical behavior of nanostructured TiO(2) thin-film electrodes in contact with aqueous electrolytes containing dissolved pollutant species is presented. The model correlates the steady-state photocurrent, the illumination intensity, and the specific photooxidation mechanism for dissolved pollutant species in...

Nanostructured semiconductors have been widely employed in (photo)-(electro)-catalytic applications. It has been demonstrated that catalyst metal nanoparticles or islands deposited on semiconducting surfaces play an important role in increasing the rate of the interfacial photoinduced charge transfer process [1,2]. Kamat et al. [3, 4] have used gol...

A kinetic model for assessing the photocatalytic degradation of water-dissolved pollutant species at suspensions of TiO2 nanoparticles is presented. The model is based on the sequence of reactions occurring at the semiconductor/electrolyte interface under illumination, and emphasizes the degree of electronic interaction of dissolved pollutant speci...

A way of extending Raman Spectroscopy to the study of adsorbates on nanostructured thin films (electrodes) is presented. A thin layer of anatase particles is deposited on a gold substrate previously roughened through electrochemical oxidation and reduction cycles in order to induce surface enhanced Raman scattering. The electromagnetic contribution...

A kinetic model based on a set of reactions occurring at the illuminated semiconductor/electrolyte junction, under current multiplication (doubling) and external applied bias (absence of recombination), was developed as a tool for assessing mechanistic aspects of photoelectrochemical oxidation of water-dissolved pollutants. The model allows to dist...

Surface mesoscopic titanium dioxide (P25) films deposited onto conducting glass plates (SnO2:F) were modified by colloidal RuxSey nanoparticles (2 nm diameter). A decrease of the photocurrent was found upon modification of TiO2 films. However, interfacial electron transfer kinetics to oxygen was favored. The increase of the catalyst surface concent...

Enunciados del examen de junio del curso 97/98. Parte de teoría.

RESUMEN La Química Física, como disciplina clásica del currículo científico en general y de la Química en particular, se estructura a partir de contenidos de diferentes áreas de conocimiento, lo que puede conducir a un estudio muy disperso, superficial y poco sistemático de la misma. La introducción del Espacio Europeo de Educación Superior (EEES)...

RESUMEN (ABSTRACT) La implantación del EEES ha promovido una profunda reestructuración en las instituciones universitarias con la finalidad de mejorar el sistema de enseñanza y evaluación. Un ejemplo es el modelo de evaluación por competencias recientemente descrito para la asignatura de Química Física Aplicada del 2º curso del Grado de Ingeniería...

RESUMEN La implantación del "Espacio Europeo de Educación Superior" surge como una prometedora apuesta para consolidar un sistema de educación que sea equiparable en toda Europa y que al mismo tiempo responda a las necesidades sociales cambiantes propias del momento actual. Según este modelo, en cada asignatura se deben alcanzar una serie de compet...

Ficha con los objetivos, programa teórico y práctico de la asignatura y bibliografía básica.

Enunciado del examen de Junio de 1997 (segunda semana). Parte de teoría.

Enunciados del examen de junio del curso 97/98. Parte de problemas.

Enunciados de examen de junio del curso 97/98. Parte de teoría (2ª semana).

Enunciados del examen de junio del curso 02/03.

Enunciados del examen del curso de doctorado de 2000.

Enunciados de doctorado del curso 2001/2002. Parte de teoría.

Enunciados del examen de doctorado del curso 2001/2002. Parte de problemas.

Enunciados del examen de doctorado del curso 2003/2004.

Guión de la práctica de laboratorio "Un estudio del ataque galvánico o bimetálico"