Desireé M. de los Santos

Desireé M. de los Santos
Universidad de Cádiz | UCA · Department of Physical Chemistry

PhD

About

46
Publications
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1,491
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Publications

Publications (46)
Article
Full-text available
To reduce greenhouse emissions and producing electricity with the smallest environmental impact, developing solar power technology is one of the most important milestones to achieve. Thus, to improve the efficiency of the concentrated solar power (CSP) plants, with lower environmental impact, is of great interest. This work reports the development...
Article
Full-text available
A nanocomposite powder of cerium and titanium oxide nanoparticles (NPs) was prepared using supercritical CO2. The characterization of the obtained powder showed spheres or quasi-spheres between 68 and 145 nm, depending on the conditions used. In all tests, N2 physisorption analysis showed that the specific surface area of the samples increased betw...
Article
Oral diseases affect to millions people worldwide. Metallic nanoparticles are used as novel treatment due to its antimicrobial, antifungal, anti-inflammatory properties. Supercritical anti-solvent process and supercritical solvent impregnation process have been used to create cerium oxide nanoparticles and impregnate them with caryophyllene oxide,...
Chapter
The impact of corrosion on titanium implants and on patient health is not well determined or elucidated based on current knowledge. Although titanium has the ability to passivate through the formation of a protective titanium oxide film and has excellent biocompatibility, it is susceptible to alteration under certain conditions. The objective of ou...
Article
Full-text available
Mango is one of the most important, medicinal tropical plants in the world from an economic point of view due to the presence of effective bioactive substances as co-products in its leaves. The aim of this work was to enhance the impregnation of natural antioxidants from mango leaves into a porous ceramic matrix. The effects of pressure, temperatur...
Article
Full-text available
Concentrating solar power (CSP) is considered a clean, renewable and sustainable energy with a significant potential to become an alternative to polluting fossil fuel-based technologies. Among CSP collectors, parabolic-trough collectors (PTC) are the most mature technology, representing nearly 90% of the currently installed collectors in CSP plants...
Preprint
The research on superhydrophobic porous materials has attracted great interest because of their ability for selective absorption of oils or organic solvents while repelling water, which convert them in excellent absorber candidates for remediation techniques. This paper shows a comparative of three different routes for the synthesis of hydrophobic...
Article
Full-text available
Silica (SiO2)/chitosan (CS) composite aerogels are bioactive when they are submerged in simulated body fluid (SBF), causing the formation of bone-like hydroxyapatite (HAp) layer. Silica-based hybrid aerogels improve the elastic behavior, and the combined CS modifies the network entanglement as a crosslinking biopolymer. Tetraethoxysilane (TEOS)/CS...
Article
Full-text available
This study introduces a new synthesis route for obtaining homogeneous chitosan (CS)-silica hybrid aerogels with CS contents up to 10 wt%, using 3-glycidoxypropyl trimethoxysilane (GPTMS) as coupling agent, for tissue engineering applications. Aerogels were obtained using the sol-gel process followed by CO2 supercritical drying, resulting in samples...
Article
Full-text available
Background Dyes are used in various sectors, such as the industry, textile, leather, and plastic industries, and part of these dyes is released in the environment via wastewater. Objective The present study aimed to investigated the surface-modified TiO2 by MoS2 and Cu. Method The effects of surface enhancement on as-prepared adsorbents on adsorp...
Chapter
Full-text available
This study reported the successful synthesis of TiO2 nanoparticles doped with Cu as photoanaodes in dye-sensitized solar cells (DSSCs). The nanoparticles were synthetized by low temperature hydrolysis and annealed at 500 °C. The obtained samples were characterized using, X-ray diffraction XRD, Raman spectroscopy. UV-Vis spectroscopy was used to det...
Chapter
This chapter contains sections titled: Introduction Materials and Methods Cu‐TiO2 Doping Al‐TiO2 Doping Tm‐TiO2 Doping Conclusions
Conference Paper
Full-text available
A new strategy for enhancing the efficiency of TiO2 dye-sensitized solar cells (DSSCs) by doping foreign ion into TiO2 lattice structure via low temperature hydrolysis process is reported. DSSCs are based on a semiconductor (i.e., TiO2), formed between a photo-sensitized anode and an electrolyte. In order to reach high conversion efficiency, it is...
Article
Full-text available
This work introduces a new synthesis procedure for obtaining homogeneous silica hybrid aerogels with carbon nanotube contents up to 2.50 wt.%. The inclusion of nanotubes in the highly porous silica matrix was performed by a two-step sol–gel process, resulting in samples with densities below 80 mg/cm³. The structural analyses (N2 physisorption and S...
Article
Full-text available
Photodegradation processes are of great interest in a range of applications, one of which is the photodecomposition of pollutants. For this reason, analysing nanoparticles that improve the efficiency of these processes under solar radiation are very necessary. Thus, in this study, TiO2 was doped with Mo and Cu using low-temperature hydrolysis as th...
Article
Uniform microparticles of vanillin were precipitated by the Rapid Expansion of Supercritical Solution (RESS) process and this reduced the commercial particle size by a factor of one hundred. A design of experiments full factorial at two levels was performed. The effects that pressure, temperature, contact time and nozzle diameter had on the particl...
Article
The paper presents an analysis of the properties of TiO2-based nanofluids such as their physical stability and heat transfer performance. The nanofluids were prepared with a eutectic mixture of diphenyl oxide and biphenyl with the addition of TiO2 nanoparticles and 1-octadecanethiol (ODT), used as a surfactant. The nanofluids were tested to determi...
Article
This paper presents the preparation of Au nanoparticles in a non-polar medium that is a fluid composed of the eutectic mixture of biphenyl and diphenyl oxide that is commonly used in Concentrating Solar Power (CSP) plants. These nanofluids showed enhanced thermal properties, presenting thermal conductivity values 70% higher than those of the base f...
Article
One of the possible research lines for improving the Concentrated Solar Power (CSP) technology is the enhancement of the thermophysical properties of the Heat Transfer Fluids (HTF) used. This enhancement leads to reduce costs for producing electricity using this technology. So, this study presents the preparation of nanofluids in which Ag nanoparti...
Article
Full-text available
The effect of the incorporation of NH 4 + into the CH 3 NH 3 + sites of the tetragonal perovskite CH 3 NH 3 PbI 3 is analysed. Also, how it affects the introduction of Cd 2+ cations into Pb 2+ sites for a perovskite with 25 at.% of NH 4 + is addressed. The incorporation of NH 4 + into perovskite leads to a dramatic loss of crystallinity and to the...
Article
This study presents the effect of the incorporation of Pd in organic-inorganic hybrid perovskite, CH3NH3PbI3. A decrease in the band gap energy of over 20% was observed in the samples with Pd, due to the presence of energy levels related with the Pd-I interaction. This feature can improve the light harvesting of this kind of material, which could h...
Article
This study presents an easy method for synthesizing highly doped TiO2 nanoparticles. The Ball Mill method was used to synthesize pure and Al-doped titanium dioxide, with an atomic percentage up to 15.7 at.% Al/(Al + Ti). The samples were annealed at 773 K, 973 K and 1173 K, and characterized using ICP-AES, XRD, Raman spectroscopy, FT-IR, TG, STEM,...
Article
This is a study of the effect of temperature and thulium doping on TiO2 nanoparticles and how it affects photocatalytic activity. The ball mill method was used to synthesize pure TiO2 and 2.0 at. %, 3.7 at. % y 4.8 at. % Tm-doped TiO2. To study the effect of Tm-doping and annealing temperature on the structural and electronic properties of the samp...
Article
Full-text available
This study presents the use of TiO2 nanoparticles with Tm as photoelectrodes in DSSCs. The nanoparticles were annealed at 1173 K and the predominant TiO2 phase was rutile. XRD and Raman spectroscopy revealed the presence of a crystalline pyrochlore phase of the mixed oxide Tm2Ti2O7. In turn, XPS confirmed the presence of Ti4+ and Tm3+, so the inclu...
Article
Full-text available
Tm-doped TiO2 nanoparticles were synthesized using a water-controlled hydrolysis reaction. Analysis was performed in order to determine the influence of the dopant concentration and annealing temperature on the phase, crystallinity, and electronic and optical properties of the resulting material. Various characterization techniques were utilized su...
Article
This study presents the incorporation of Al-(hydr)oxide species onto the surface of TiO2 nanoparticles used as photoelectrodes in dye-sensitized solar cells. The semiconductors prepared were comprehensively characterized by means of atomic absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and U...
Article
This paper presents the synthesis of organic-inorganic hybrid perovskite, CH3NH3PbI3, doped in Pb2+ position with Sn2+, Sr2+, Cd2+ and Ca2+. The incorporation of the dopants into the crystalline structure was analysed, observing how the characteristics of the dopant affected properties such as the crystalline phase, emission and optical properties....
Article
A new software (UCA-FUKUI) has been developed to facilitate the theoretical study of chemical reactivity. This program can calculate global parameters like hardness, softness, philicities, and Fukui condensed functions, and also local parameters from the condensed functions. To facilitate access to the program we have developed a very easy-to-use i...
Article
A process for the SAS coprecipitation of ibuprofen with the polymers poly(L-lactic acid) and Eudragit L100 was successfully carried out. The particle size was reduced to micrometer and near nanometer ranges. The morphology of the raw material changed to spherical upon processing for both poly(L-lactic acid)/ibuprofen particles and eudragit/ibuprofe...
Article
Highly aluminium-doped TiO2 nanoparticles were synthesized using a sol–gel method. The synthesized nanoparticles were annealed at different temperatures and their properties were characterized using ICP-AES, XRD, Raman spectroscopy, FT-IR, XPS, and UV-Vis to determine their composition, crystalline structure, band gap energy and possible use as sem...
Article
A Project Based Learning (PBL) methodology was used in the practical laboratories of the Advanced Physical Chemistry department. The project type proposed simulates "real research" focusing on sol gel synthesis and the application of the obtained sol as a stone consolidant. Students were divided into small groups (2 to 3 students) to simulate a rea...
Article
This is an experimental and theoretical study of thulium doped TiO2 nanoparticles. From an experimental perspective, a method was used to synthesize thulium-doped TiO2 nanoparticles in which Tm3+ replaces Ti4+ in the lattice, which to our knowledge has neither been reported nor studied theoretically before. Different proportions of anatase and ruti...
Article
This study presents the experimental and theoretical study of highly internally Al-doped TiO2 nanoparticles. Two synthesis methods were used and detailed characterization was performed. There were differences in the doping and the crystallinity, but the nanoparticles synthesized with the different methods share common features. Anatase to rutile tr...
Article
We report a theoretical study of a series of Ru complexes of interest in dye-sensitised solar cells, in organic light-emitting diodes, and in the war against cancer. Other metal centres, such as Cr, Co, Ni, Rh, Pd, and Pt, have been included for comparison purposes. The metal–ligand trends in organometallic chemistry for those compounds are shown s...
Article
Cu-doped TiO2 nanoparticles were synthesized for use as photoanodes in dye-sensitized solar cells (DSSCs). The nanoparticles were characterized by using inductively coupled plasma atomic emission spectroscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning transmission electron microscopy and UV-Vis spectroscopy....
Article
A good correlation was obtained between the electronic properties of Cu-doped anatase TiO2 by virtue of both physical chemistry characterization and theoretical calculations. Pure and Cu-doped TiO2 were synthesized. The composition, structural and electronic properties, and the band gap energy were obtained using several techniques. The method of s...
Article
Full-text available
A customary procedure in the protection of monumental buildings is the consolidation of decaying stone by the application of commercial products containing tetraethoxysilane (TEOS). These products polymerize within the porous structure of the decaying stone, significantly increasing the cohesion of the material. However, TEOS-based consolidants suf...
Article
A challenging objective in monumental stone restoration is to synthesize crack-free silica materials for application as consolidants. Hydrophobicity is also a valuable property for such products; it is important to prevent the penetration of water because water is the main vehicle by which the agents of decay enter the pore structure of the stone....
Article
Full-text available
The sol-gel process has been found to be successful in applications for the conservation and restoration of stone. However, a well-known drawback of the materials obtained by this process is their tendency to crack during drying inside the pores of the treated stone. In this article, we present an overview of our current research centred on produci...
Article
A novel sol-gel synthesis, in which a surfactant acts to make the pore size of the gel network more coarse and uniform, is shown to provide an effective alternative for the consolidation of stone. The new mesoporous silica avoids the main inconvenience of current commercial consolidants, which is their tendency to crack inside the pores of the ston...
Article
We propose an innovative strategy to obtain crack-free gels by using a surfactant as a template for the silica pores. We use a neutral surfactant –n-octylamine – which weakly interacts by hydrogen bonding with the silica precursor. This allows it to be removed by simple drying in ambient air. We investigate the effect of the surfactant in simple in...

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