Photothermal Catalytic CO Conversion: Beyond Catalysis and Photocatalysis.

In recent years, the combination of both thermal and photochemical contributions has provided interesting opportunities for solar upgrading of catalytic processes. Photothermal catalysis works at the interface between purely photochemical processes, which involve the direct conversion of photon energy into chemical energy, and classical thermal catalysis, in which the catalyst is activated by temperature. Thus, photothermal catalysis acts in two different ways on the energy path of the reaction.

Improved Methane Production by Photocatalytic CO Conversion over Ag/InO/TiO Heterojunctions.

In this work, the role of InO in a heterojunction with TiO is studied as a way of increasing the photocatalytic activity for gas-phase CO reduction using water as the electron donor and UV irradiation. Depending on the nature of the employed InO, different behaviors appear. Thus, with the high crystallite sizes of commercial InO, the activity is improved with respect to TiO, with modest improvements in the selectivity to methane.

Irradiance-Controlled Photoassisted Synthesis of Sub-Nanometre Sized Ruthenium Nanoparticles as Co-Catalyst for TiO in Photocatalytic Reactions.

Photoassisted synthesis is as a highly appealing green procedure for controlled decoration of semiconductor catalysts with co-catalyst nanoparticles, which can be carried out without the concourse of elevated temperatures, external chemical reducing agents or applied bias potential and in a simple slurry reactor. The aim of this study is to evaluate the control that such a photoassisted method can exert on the properties of ruthenium nanoparticles supported on TiO by means of the variation of the incident irradiance and hence of the photodeposition rate. For that purpose, different Ru/TiO systems with the same metal load have been prepared under varying irradiance and characterized by means of elemental analysis, transmission electron microscopy and X-ray photoelectron spectroscopy.

Synergism in TiO photocatalytic ozonation for the removal of dichloroacetic acid and thiacloprid.

The synergistic effect of the photocatalytic ozonation process (PH-OZ) using the photocatalyst TiO is usually attributed to influences of the physicochemical properties of the catalyst, pollutant type, pH, temperature, O concentration, and other factors. It is also often claimed that good adsorption on the TiO surface is beneficial for the occurrence of synergism. Herein, we tested these assumptions by using five different commercial TiO photocatalysts (P25, PC500, PC100, PC10 and JRC-TiO-6) in three advanced oxidation systems - photocatalysis (O/TiO/UV), catalytic ozonation (O/TiO) and PH-OZ (O/TiO/UV) - for the degradation of two pollutants (dichloroacetic acid - DCAA and thiacloprid) simultaneously present in water.

Ti-Modified LaFeO/β-SiC Alveolar Foams as Immobilized Dual Catalysts with Combined Photo-Fenton and Photocatalytic Activity.

Ti-modified LaFeO/β-SiC alveolar foams were used as immobilized, highly robust dual catalysts with combined photocatalytic wet peroxide oxidation and photocatalytic activity under UV-A light. They were prepared by incipient wetness impregnation of a β-SiC foam support, by implementing a sol-gel Pechini synthesis at the foam surface in the presence of dried amorphous sol-gel titania as a titanium source. The physicochemical and catalytic features suggest the stabilization at the foam surface of a substituted LaTiFeO catalyst analogous to its powdery counterpart.

Activity enhancement pathways in LaFeO@TiO heterojunction photocatalysts for visible and solar light driven degradation of myclobutanil pesticide in water.

LaFeO@TiO heterojunction composites with a core-shell porous structure and LaFeO contents in the 2.5-25 wt.% range have been synthesized via consecutive sol-gel syntheses and tested for the photocatalytic oxidation of the myclobutanil pesticide in water under solar light and pure visible light.

Recent Achievements in Development of TiO-Based Composite Photocatalytic Materials for Solar Driven Water Purification and Water Splitting.

Clean water and the increased use of renewable energy are considered to be two of the main goals in the effort to achieve a sustainable living environment. The fulfillment of these goals may include the use of solar-driven photocatalytic processes that are found to be quite effective in water purification, as well as hydrogen generation. H production by water splitting and photocatalytic degradation of organic pollutants in water both rely on the formation of electron/hole (e/h) pairs at a semiconducting material upon its excitation by light with sufficient photon energy.

TiO Nanocolumn Arrays for More Efficient and Stable Perovskite Solar Cells.

Organic-inorganic hybrid perovskite solar cells have attracted much attention due to their high power conversion efficiency (>25%) and low-cost fabrication. Yet, improvements are still needed for more stable and higher-performing solar cells. In this work, a series of TiO nanocolumn photonic structures have been intentionally fabricated on half of the compact TiO-coated fluorine-doped tin oxide substrate by glancing angle deposition with magnetron sputtering, a method particularly suitable for industrial applications due to its high reliability and reduced cost when coating large areas.

Ferrite Materials for Photoassisted Environmental and Solar Fuels Applications.

Ferrites are a large class of oxides containing Fe and at least another metal cation that have been investigated for and applied to a wide variety of fields ranging from mature technologies like circuitry, permanent magnets, magnetic recording and microwave devices to the most recent developments in areas like bioimaging, gas sensing and photocatalysis. In the last respect, although ferrites have been less studied than other types of semiconductors, they present interesting properties such as visible light absorption, tuneable optoelectronic properties and high chemical and photochemical stability. The versatility of their chemical composition and of their crystallographic structure opened a playground for developing new catalysts with enhanced efficiency.

Carbon nanotube synthesis and spinning as macroscopic fibers assisted by the ceramic reactor tube.

Macroscopic fibers of carbon nanotubes (CNT) have emerged as an ideal architecture to exploit the exceptional properties of CNT building blocks in applications ranging from energy storage to reinforcement in structural composites. Controlled synthesis and scalability are amongst the most pressing challenges to further materialize the potential of CNT fibers. This work shows that under floating catalyst chemical vapor conditions in the direct spinning method, used both in research and industry, the ceramic reactor tube plays an unsuspected active role in CNT growth, leading for example to doubling of reaction yield when mullite (AlSiO(x ≈ 0:4)) is used instead of alumina (AlO), but without affecting CNT morphology in terms of number of layers, purity or degree of graphitization.

Influence of Post-Synthesis Modifications of TiZrO₂ Nanocrystallites on Their Photocatalytic Activity for Toluene and Methylcyclohexane Degradation.

The modification of the structural and surface characteristics of TiZrO₂ nanocrystallites by postsynthesis treatments is revealed as an effective way to enhance their photocatalytic activity. Starting with the same batch of mixed oxide prepared from reverse microemulsions, different photocatalysts have been obtained by either solvothermal treatment, calcination or a combination of both. Extensive physicochemical characterization of the resulting materials shows that solvothermally treated oxides present lower crystallite size and larger surface area, although without previous calcination these samples appear to have a higher degree of structural disorder.

Evaluation of photoassisted treatments for norfloxacin removal in water using mesoporous FeO-TiO materials.

We report the synthesis of mesoporous TiO and mesoporous FeO-TiO catalysts by using a structure-directing-surfactant method, their characterization and their employment as photocatalysts for norfloxacin degradation in aqueous solution. The main findings show that in the presence of both O and HO, Fe-containing mesoporous titania (FeO-TiO), with iron percentages between 1 and 3 wt%, exhibited norfloxacin degradation rates more than 60% greater than otherwise identical mesoporous titania without iron. Furthermore, the activity of the mesoporous composite catalysts also exceeds that of titania when illuminated with 405 nm light-emitting diodes.

Mechanistic View of the Main Current Issues in Photocatalytic CO Reduction.

After 40 years of research on photocatalytic CO reduction, there are still many unknowns about its mechanistic aspects even for the most common TiO-based photocatalytic systems. These uncertainties include the pathways inducing visible-light activity in wide-band gap semiconductors, the charge transfer between semiconductors and plasmonic metal nanoparticles, the unambiguous determination of the origin of C-bearing products, the very first step in the activation of the CO molecule, the factors determining the selectivity, the reasons for photocatalyst deactivation, the closure of the catalytic cycle by the hole-scavenging reagent, and the detailed reaction pathways and the most suitable techniques for their determination. This Perspective discusses these controversial issues based on the most relevant investigations reported so far.

Unravelling the effect of charge dynamics at the plasmonic metal/semiconductor interface for CO photoreduction.

Sunlight plays a critical role in the development of emerging sustainable energy conversion and storage technologies. Light-induced CO reduction by artificial photosynthesis is one of the cornerstones to produce renewable fuels and environmentally friendly chemicals. Interface interactions between plasmonic metal nanoparticles and semiconductors exhibit improved photoactivities under a wide range of the solar spectrum.

CO reduction over NaNbO and NaTaO perovskite photocatalysts.

The activity of NaNbO and NaTaO perovskites for the photocatalytic reduction of CO is studied in this work. For this purpose, sodium niobate and tantalate have been prepared using solid-state reactions, extensively characterised by means of powder X-ray diffraction, UV-vis, photoluminescence and Raman spectroscopies and N adsorption isotherms, and tested in the gas-phase reduction of CO under UV light in a continuous flow photoreactor. NaNbO is constituted of an orthorhombically distorted perovskite structure, while a ca.

Ga-Promoted Photocatalytic H2 Production over Pt/ZnO Nanostructures.

Photocatalytic H2 generation is investigated over a series of Ga-modified ZnO photocatalysts that were prepared by hydrothermal methods. It is found that the structural, textural, and optoelectronic properties remarkably depend on the Ga content. The photocatalytic activity is higher in samples with Ga content equal to or lower than 5.

Molecular classification of non-muscle-invasive bladder cancer (pTa low-grade, pT1 low-grade, and pT1 high-grade subgroups) using methylation of tumor-suppressor genes.

The role of epigenetics in distinguishing pathological and clinical subgroups in bladder cancer is not fully characterized. We evaluated whether methylation of tumor-suppressor genes (TSGs) would classify non-muscle-invasive (NMI) bladder cancer subgroups and predict outcome. A retrospective design included the following paraffin-embedded primary NMI tumor types (n = 251): pTa low grade (LG) (n = 79), pT1LG (n = 81), and pT1 high grade (HG) (n = 91).

Highly active photocatalytic coatings prepared by a low-temperature method.

Photocatalytic properties of titanium (IV) oxide (TiO2) in anatase form can be used for various purposes, including photocatalytic purification of water. For such an application, suspended or fixed photocatalytic reactors are used. Those with fixed phase seem to be preferred due to some advantages, one of which is the avoidance of photocatalyst filtration.

Analysis of MYB oncogene in transformed adenoid cystic carcinomas reveals distinct pathways of tumor progression.

Adenoid cystic carcinomas can occasionally undergo dedifferentiation, a phenomenon also referred to as high-grade transformation. However, cases of adenoid cystic carcinomas have been described showing transformation to adenocarcinomas that are not poorly differentiated, indicating that high-grade transformation may not necessarily reflect a more advanced stage of tumor progression, but rather a transformation to another histological form, which may encompass a wide spectrum of carcinomas in terms of aggressiveness. The aim of this study was to gain more insight in the biology of this pathological phenomenon by means of genetic profiling of both histological components.

Synthesis of BiVO4/TiO2 composites and evaluation of their photocatalytic activity under indoor illumination.

BiVO4/TiO2 composites with different weight ratios have been prepared by coprecipitation-based reactions followed by either thermal or hydrothermal treatment with the aim of evaluating the TiO2 photosensitization by BiVO4. The obtained materials present in all cases the desired monoclinic phase of BiVO4 and anatase phase of TiO2. Visible light absorption increased with increasing amount of bismuth vanadate.

Surface functionalization of nanostructured Fe2O3 polymorphs: from design to light-activated applications.

Nanostructured iron(III) oxide deposits are grown by chemical vapor deposition (CVD) at 400-500 °C on Si(100) substrates from Fe(hfa)2TMEDA (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N',N'-tetramethylethylenediamine), yielding the selective formation of α-Fe2O3 or the scarcely studied ε-Fe2O3 polymorphs under suitably optimized preparative conditions. By using Ti(OPr(i))4 (OPr(i) = iso-propoxy) and water as atomic layer deposition (ALD) precursors, we subsequently functionalized the obtained materials at moderate temperatures (<300 °C) by an ultrathin titanomagnetite (Fe3-xTixO4) overlayer. An extensive multitechnique characterization, aimed at elucidating the system structure, morphology, composition and optical properties, evidenced that the photoactivated hydrophilic and photocatalytic behavior of the synthesized materials is dependent both on iron oxide phase composition and ALD surface modification.

Polyamine-modulated factor-1 methylation predicts Bacillus Calmette-Guérin response in patients with high-grade non-muscle-invasive bladder carcinoma.

Background: Bacillus Calmette-Guérin (BCG) is a standard treatment to reduce tumor recurrence and delay progression of high-risk non-muscle-invasive (NMI) bladder tumors. However, it is not clear yet which patients are more likely to respond to BCG.

Objective: The aim was to evaluate the role of polyamine-modulated factor-1 (PMF-1) methylation in predicting clinical outcome of T1 high-grade (T1HG) bladder tumors treated with BCG.

V-doped SnS2: a new intermediate band material for a better use of the solar spectrum.

Intermediate band materials can boost photovoltaic efficiency through an increase in photocurrent without photovoltage degradation thanks to the use of two sub-bandgap photons to achieve a full electronic transition from the valence band to the conduction band of a semiconductor structure. After having reported in previous works several transition metal-substituted semiconductors as able to achieve the electronic structure needed for this scheme, we propose at present carrying out this substitution in sulfides that have bandgaps of around 2.0 eV and containing octahedrally coordinated cations such as In or Sn.