Methane is a valuable resource and its valorization is an important challenge in heterogeneous catalysis. Here it is shown that CeO2/CuO composite prepared by ball milling activates methane at a temperature as low as 250 degrees C. In contrast to conventionally prepared catalysts, the formation of partial oxidation products such as methanol and formaldehyde is also observed. Through an in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) and operando Near Edge X-Ray Absorption Fine Structure Spectroscopy (NEXAFS) approach, it can be established that this unusual reactivity can be attributed to the presence of Ce4+/Cu+ interfaces generated through a redox exchange between Ce3+ and Cu2+ atoms facilitated by the mechanical energy supplied during milling. DFT modeling of the electronic properties confirms the existence of a charge transfer mechanism. These results demonstrate the effectiveness and distinctiveness of the mechanical approach in creating unique and resilient interfaces thereby enabling the optimization and refining of CeO2/CuO catalysts in methane activation reactions.

Hematite is a promising catalyst to remove nitrogen oxide (NOx, x = 1 and 2) pollutants from the atmosphere. Improving its catalytic performance requires a clear understanding of the relevant surface processes, including NOx adsorption. Prior theoretical simulations were limited to isolated adsorbates at static conditions, with results not fully consistent with experiments. Here, we investigate the adsorption of NOx molecules on the hematite (0001) surface by using the density functional theory + U method with van der Waals corrections. We find that, at static conditions, NOx prefer to occupy two neighboring surface Fe and O sites simultaneously, due to a cooperative effect between two open-shell NOx molecules [J. Phys. Chem. B 2002, 106, 7405-7413]. In contrast, isolated adsorbates are favored at high temperatures (T) or low NOx partial pressures (PNOx) due to their higher configurational entropy. A surface phase diagram is constructed for the NOx adsorbates, delineating both their stability fields and equilibrium coverages. As the structure and abundance of NOx adsorbates depend strongly on T and PNOx, surface reactions at different T-PNOx conditions may follow quite different pathways.

Ullmann coupling is a widely used reaction for the on-surface growth of low-dimensional carbon nanomaterials. The irreversible nature of this reaction prevents the "self-healing" of defects, and a detailed knowledge of its mechanism is therefore essential to enable the growth of extended ordered structures. However, the dynamics of the Ullmann polymerization remain largely unexplored, as coupling events occur on a timescale faster than conventional scanning probe microscopy imaging frequencies. Here, we reveal the dynamics of these surface events using high-speed variable-temperature scanning tunneling microscopy (STM) (10 frames per second). Performing the measurements at the onset reaction temperatures provides an unprecedented description of the evolution of organometallic (OM) and covalent surface species during the Ullmann polymerization of para-dibromobenzene on Cu(110). Our results demonstrate the existence of an intermediate OM phase with Cu adatoms that inhibits the polymerization. These observations now complete the picture of the pathways of on-surface Ullmann polymerization, which includes the complex interplay of the phenylene moieties and metal atoms. Our work demonstrates the unique capability of high-speed STM to capture the dynamics of molecular self-assembly and coupling.

Introduction Pressure injuries (PIs) are a significant issue in healthcare system: nursing students are recommended to be prepared to assess the risk, prevent and manage them. However, despite the coronavirus disease-2019 (COVID-19) pandemic significantly affected nursing students’ learning opportunities no data regarding their impact of PIs knowledge, attitudes and learning occasions have been documented to date. Aims To describe the post-pandemic knowledge and attitudes regarding PI prevention and management and to compare clinical learning opportunities in the field of PIs before and after the COVID-19 pandemic. Method A descriptive multi-method study involving students at the time of their graduation in the before (n=114) and after the pandemic (n=113). The Italian versions of the Pressure Ulcer Knowledge Assessment Tool (PUKAT-IT) and Attitude Toward Pressure Ulcer Prevention (APuP-IT) scales were used. Data regarding pre- and post-pandemic learning opportunities were retrospectively collected from the Student Portfolio of Skills. Results The average PUKAT-IT score was 57.92% (cut-off 60%), which indicates insufficient knowledge; the average APuP-IT score was 78.19% (cut-off 75%), which shows positive attitudes towards PI. Comparing the pre- and the post-pandemic groups, learning opportunities in PI risk assessment and prevention significantly decreased (overall 38.90 vs 32.27 and 35.26 vs 25.97, respectively) while those regarding the PI management remained stable. Conclusion In the post-pandemic times, nursing students’ knowledge about PIs remains insufficient while their attitudes are adequate; the pandemic significantly reduced students’ exposure to prevention and assessment learning opportunities during their internship, which suggests a need to update educational strategies to ensure appropriate knowledge and learning experiences in this field.

Electronic metal support interaction in the Pt/Co3O4(111) model catalysts involves cation exchange yielding atomically dispersed Pt2+ and Pt4+ species. In the presence of water, these can be stabilized in the form of triaqua complexes.

The present work focuses on the catalytic activity of Pt nanoclusters as well as single-atom Pt catalysts supported by TiO2 and Co3O4. We performed an extensive set of calculations based on density functional theory to investigate the CO oxidation reaction on Pt clusters supported on TiO2 and Co3O4 surfaces. We identified the catalytic active sites at the interface between the supported metal and the metal oxide substrate, and we determined different oxidation reaction pathways, proceeding either through the Langmuir-Hinshelwood (LH) or Mars-van Krevelen (MvK) mechanisms. Comparing clusters of different sizes, our calculations suggest that the Pt-1/TiO2 catalyst, where Pt is present as an adatom or substituting a Ti site, is the most active catalyst for CO oxidation. We find that the kinetics of the reaction on Pt nanoclusters is highly dependent on the size of the metal cluster but does not follow a well-defined trend. Moreover, the kinetics of the reaction is remarkably influenced by the type of supporting metal oxides.

The formation of the metal-oxide interface in the Pd/Co3O4(111) model catalyst was investigated by means of density functional theory (DFT), synchrotron radiation photo-electron spectroscopy (SRPES), and scanning tunneling micros-copy (STM). The electronic metal-support interaction results in a substantial charge transfer at the interface yielding atomically dispersed Pd2+ species and partially oxidized Pd delta + aggregates coupled with a partial reduction of Co3O4(111). Atomically dispersed Pd2+ species at the fcc site on the Co3O4(111) surface were found to be the most energetically favorable configuration. In comparison to the dispersed Pd2+ species, the formation of Pd dimers, trimers, and tetramers was found to be less favorable. The analysis of the Bader charges revealed a substantial net positive charge on Pd atoms in dimers, trimers, and tetramers which is consistent with the formation of partially oxidized Pd delta+ aggregates detected by SRPES. The analysis of the charge distribution in Co3O4(111) revealed a partial reduction of Co3+ to Co2+ cations in the first and second Co layers. According to DFT, Pd delta+ aggregates are prone to oxidation to PdO in the presence of O2 and H2O. The partially oxidized Pd delta + and Pd4Ox aggregates form 1 to 2 monolayer thick clusters which serve as nuclei for the growth of metallic Pd0 nanoparticles. At high Pd coverage, Pd nanoparticles coalesce resulting in the growth of two-dimensional islands that densely cover the Co3O4(111) substrate.

Heterogeneous catalysts based on Pt nanoparticles supported on oxides are used in a number of important catalytic processes, including oxidation of hydrocarbons and redox reactions in PEM fuel cells. The interaction with gas-phase oxygen is often a key component of the target chemistry and can affect the reactivity of the clusters because of their oxidation. Recent experiments have shown that the oxidation of Pt nanoparticles is influenced by a number of factors, including the clusters size and the interaction with the support, leading to properties that can differ substantially from those of larger samples. Here we combine density functional theory, the genetic algorithm, and ab initio thermodynamics to investigate the structure and the oxidizability of small Pt-x (x = 1-8) nanoparticles. We find that the interaction of oxygen with Pt depends strongly on the size of the clusters, leading to facile oxidation of Pt nanoparticles. The interaction with the oxide supports studied in this work, brookite TiO2 and Co3O4, hinders the oxidizability compared to the gas phase. At conditions of temperature and pressure typically encountered in catalytic oxidation reactions, Pt nanoparticles are predicted to be oxidized, at variance with the bulk counterpart. Our results highlight the importance of low Pt-Pt coordination in the interaction with oxygen and the role of the interaction with oxide supports.

Single-atom catalysts represent an essential and ever-growing family of heterogeneous catalysts. Recent studies indicate that besides the valuable catalytic properties provided by single-atom active sites, the presence of single-atom sites on the catalyst substrates may significantly influence the population of supported metal nanoparticles coexisting with metal single atoms. Treatment of ceria-based single-atom catalysts in oxidizing or reducing atmospheres was proven to provide precise experimental control of the size of the supported Pt nanoparticles, and, correspondingly, control of catalyst activity and stability. Based on dedicated surface science experiments, ab-initio calculations and kinetic Monte-Carlo simulations we demonstrate that the morphology of Pt nanoparticle population on ceria surface is a result of a competition for Pt atoms between Pt single-atom sites and Pt nanoparticles. In oxidizing atmosphere, Pt single-atom sites provide strong bonding to single Pt atoms and Pt nanoparticles shrink. In reducing atmosphere, Pt single atom sites are depopulated and Pt nanoparticles grow. We formulate a generic model of Pt redispersion and coarsening on ceria substrates. Our model provides a unified atomic-level explanation for a variety of metal nanoparticle dynamic processes observed in single-atom catalysts under stationary or alternating oxidizing/reducing atmospheres, and allows to classify the conditions when nanoparticle ensembles on single-atom catalysts substrates can be stabilized against Ostwald ripening.

Background Nursing education has been disrupted by the onset of the COronaVIrus Disease 19 (COVID-19) pandemic, potentially impacting learning experiences and perceived competencies at the time of graduation. However, the learning experiences of students since the onset of COVID-19, their perceived competences achieved and the employment status one month after graduation, have not been traced to date. Methods A cross sectional online survey measured the individual profile, the learning experience in the last academic year and the perceived competences of the first COVID-19 new nursing graduates in two Italian universities. Details relating to employment status and place of employment (Covid-19 versus non-COVID-19 units) one month after graduation were also collected and the data compared with those reported by a similar cohort of new graduates pre-pandemic in 2018–2019. All those who graduated in November 2020 and attended their third year after the onset of the COVID-19 pandemic were eligible. The online survey included individual, nursing programme and first working experience variables alongside the Nurse Competence Scale (NCS). Descriptive and inferential statistical analyses were performed. Results A total of 323 new graduates participated. In their last academic year, they experienced a single, long clinical placement in non-COVID-19 units. One month after graduation, 54.5% ( n = 176) were working in COVID-19 units, 22.9% ( n = 74) in non-COVID-19 units and 22.6 ( n = 73) were unemployed. There was no statistical difference among groups regarding individual variables and the competences perceived. Fewer new graduates working in COVID-19 units experienced a transition programme compared to those working in non-COVID-19 units ( p = 0.053). At the NCS, the first COVID-19 new graduate generation perceived significantly lower competences than the pre-COVID-19 generation in the ‘Helping role’ factor and a significant higher in ‘Ensuring quality’ and ‘Therapeutic interventions’ factors. Conclusions The majority of the first COVID-19 new graduate generation had been employed in COVID-19 units without clinical experience and transition programmes, imposing an ethical debate regarding (a) the role of education in graduating nurses in challenging times with limited clinical placements; and (b) that of nurse managers and directors in ensuring safe transitions for new graduates. Despite the profound clinical placement revision, the first COVID-19 new graduate generation reported competences similar to those of the pre-COVID-19 generation, suggesting that the pandemic may have helped them to optimise the clinical learning process.

NOx(x=1,2)are major air-pollutants detrimental to human health and much effort has been devoted to find efficient photocatalysts capable of removing NOx from air(de-NOx).Recent experiments indicate that hematite(α-Fe2O3)is a promising de-NOx photocatalyst.However some key features of the NO adsorption on the hematite surface remain unclear,hindering further comprehension of the photocatalytic process.Here we study the adsorption of NO on the hematite(0001)surface using the PBE+U method with a dispersion correction(vdw)in the framework of density functional theory(DFT).We find the addition of a Hubbard U term in the DFT Hamiltonian strongly affects the adsorption properties,with the adsorption energy(-0.64 eV)decreased by 50％with respect to those of PBE(-1.31 eV).This decrease is attributed to two factors;(i)the U term shifts the energy of Fe 3d orbitals away from the valence band maximum,making them chemically less active;(ii)the NO molecule has an unpaired π* electron and is more sensitive to the electronic structure of the substrate.In contrast to the inclusion of U,the dispersion correction causes little change to the adsorption properties except increases the adsorption energy by about-0.18 eV.We use the Langmuir formula to calculate the thermal equilibrium coverage of NO on the hematite(0001)surface and find predictions made with the PBE+U vdw are more consistent with experiments.These results highlight the importance of strong electronic correlations in describing the hematite surface reactions,and may serve as a starting point to unravel the complete photocatalytic mechanism.

Il monitoraggio dei pazienti con insufficienza respiratoria utilizzando SpO2 da solo non esprime la gravità della malattia rispetto alla malattia polmonare. Attraverso il punteggio dell'ecografia polmonare (LUS), è forse meglio valutare il punteggio di aerazione del paziente e seguirlo nel tempo.

The oxygen evolution reaction (OER) plays a crucial role in (photo)electrochemical devices that use renewable energy to produce synthetic fuels. Recent measurements on semiconducting oxides have found a power law dependence of the OER rate on surface hole density, suggesting a multihole mechanism. In this study, using transient photocurrent measurements, density functional theory simulations and microkinetic modelling, we have uncovered the origin of this behaviour in haematite. We show here that the OER rate has a third-order dependence on the surface hole density. We propose a mechanism wherein the reaction proceeds by accumulating oxidizing equivalents through a sequence of one-electron oxidations of surface hydroxy groups. The key O–O bond formation step occurs by the dissociative chemisorption of a hydroxide ion involving three oxyl sites. At variance with the case of metallic oxides, the activation energy of this step is weakly dependent on the surface hole coverage, leading to the observed power law.

CuFeO2 is a p-type semiconductor that has been recently identified as a promising photocathode material for photoelectrochemical water splitting. CuFeO2 can absorb solar light and promote the hydrogen evolution reaction (HER), even though the photocurrents achieved so far are still well below the theoretical upper limit. While several experimental and theoretical works have provided a detailed characterization of the bulk properties of this material, surfaces have been largely unexplored. In this work, we perform first-principles simulations based on DFT to investigate the structure, electronic properties, and thermodynamic stability of CuFeO2 surfaces both in vacuum and in an electrochemical environment. To estimate the alignment of the band edges on the electrochemical scale, we perform ab initio molecular dynamics in explicit water, unraveling the structure of the solid/liquid interface for various surface terminations. We consider the system both in the dark and under illumination, showing that light absorption can induce partial reduction of the surface, giving rise to states in the gap that can pin the Fermi level, in agreement with recent measurements. Using the free energy of adsorption of atomic hydrogen as a descriptor of the catalytic activity for the HER, we show that hydride species formed at oxygen vacancies can be highly active and could therefore be an intermediate of reaction.

Model catalysts, where the structure of single-crystal materials with well-defined surface terminations can be determined at the atomic level, are useful systems to perform fundamental studies on electrocatalysis. The magnetite Fe3O4(001) surface, in particular, has been the focus of several studies aimed at characterizing its structure in vacuum in the presence of a water layer and interfaced with liquid water-based electrolytes. Recently, this system has also been investigated as a catalyst for the oxygen evolution reaction (OER), with the goal of correlating structural properties of the interface with catalytic performance and mechanism. In this work, we use first-principles simulations based on density functional theory to establish the structural, thermodynamic, and electronic properties of the Fe3O4(001) surface in contact with water. We compute the phase diagram of the magnetite/water system and address some open issues on the structural transitions observed experimentally among different surface terminations. We then address the stability in electrochemical environments, and we investigate the OER mechanism, considering reaction paths involving both terminal and bridging oxygen atoms. We find that different surface reconstructions can promote OER via different reaction sites and potential-determining steps, albeit with a similar energy cost. In particular, the bulk-truncated termination promotes OER via terminal oxygen atoms, and the potential-determining step is the dehydrogenation of the *OH group. On the (root 2 x root 2 )R45 degrees reconstruction, on the other hand, OER proceeds via the bridging oxygen atoms, and the potential-determining step is the formation of the hydroperoxo.

OBJECTIVE:To summarize the experience of individuals placed in quarantine during an outbreak.DESIGN:A meta-summary and a meta-synthesis based upon a systematic review of qualitative studies.SAMPLE:The Cumulative Index of Nursing and Allied Health Literature, MEDLINE, and Scopus databases were all searched up to April 2020.MEASUREMENTS:The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed; then, the methodological quality of the studies included was assessed with the Critical Appraisal Screening Programme tool for qualitative studies.RESULTS:Five studies have been included documenting the experience of 125 adult individuals. A total of 16 codes emerged: in the meta-summary, the most and least frequent codes were "Thinking about quarantine" (80%) and "Emotional roller coaster," "Being alert for any symptom," "Trusting or not?," "Knowing who brought the infection," and "Living in a surreal world" (20%). The codes which emerged were categorized into three main themes which summarized the whole experience of being placed in quarantine: (a) "Being swamped with a thousand emotions"; (b) "Being restrained"; and (c) "Needing to be considered."CONCLUSIONS:The experience of quarantine for people is a long journey which can feel chaotic due to uncertainty about the consequences on health, work, and the future. The findings of this study can help nurses in caring for quarantined individuals by enabling them to understand people's need for educational and emotional support. Ensuring the supply of consistent information is also important to increase people's compliance.

The cuprous delafossite, CuFeO2, has received significant attention in recent years as a potential photocathode material in photoelectrochemical water-splitting cells. Presented herein is an investigation of the electronic structure of CuFeO2 in the framework of density functional theory. We have benchmarked three of the most popular formulations for the treatment of the electron exchange and correlation interactions, highlighting their strengths and weaknesses in predicting electronic structures compatible with the available spectroscopic measurements. Although some features are correctly reproduced by the simplest approach, which is based on the generalized gradient approximation, this fails in describing the fundamental semiconducting character of the material. The introduction of the fully self-consistent Hubbard U correction in the exchange correlation functional accounts explicitly for the on-site Coulomb interaction among localized d electrons, thereby opening a gap in the band structure. However, our results indicate that the U correction disrupts the crystal-field splitting of the t(2g) and e(g) states, resulting in an inaccurate description of the conduction-band edge. We provide a qualitative and quantitative analysis to explain why the t(2g) and e(g) states behave differently when the Hubbard correction is switched on. We find that best practice for accurate, yet computationally viable, simulations of CFO makes use of hybrid functionals, where the fraction of exact exchange is not arbitrarily selected but tuned according to the static dielectric constant of the material. In this case, theoretical predictions are found to be in excellent agreement with experimental results.

Oxygen vacancies are known to play a crucial role in tuning the physical properties and technological applications of titanium dioxide TiO2. Over the last decades, defects in substoichiometric TiO2 have been commonly associated with the formation of TinO2n-x Magnéli phases, which are extended planar defects originating from crystallographic shear planes. By combining advanced transmission electron microscopy techniques, electron energy-loss spectroscopy and atomistic simulations, we reach new understanding of the oxygen vacancy induced structural modulations in anatase, ruling out the earlier shear-plane model. Structural modulations are instead shown to be due to the formation of oxygen vacancy superstructures that extend periodically inside the films, preserving the crystalline order of anatase. Elucidating the structure of oxygen defects in anatase is a crucial step for improving the functionalities of such material system and to engineer devices with targeted properties.