RESULTS FROM 1 TO 20 OF 3260

2024, Articolo in rivista, ENG

Structural and Photoelectronic Properties of k-Ga2O3 Thin Films Grown on Polycrystalline Diamond Substrates

Marco Girolami, Matteo Bosi, Sara Pettinato, Claudio Ferrari, Riccardo Lolli, Luca Seravalli, Valerio Serpente, Matteo Mastellone, Daniele M. Trucchi, Roberto Fornari

Orthorhombic k-Ga2O3 thin films were grown for the first time on polycrystalline diamond free-standing substrates by metal-organic vapor phase epitaxy at a temperature of 650 °C. Structural, morphological, electrical, and photoelectronic properties of the obtained heterostructures were evaluated by optical microscopy, X-ray diffraction, current-voltage measurements, and spectral photoconductivity, respectively. Results show that a very slow cooling, performed at low pressure (100 mbar) under a controlled He flow soon after the growth process, is mandatory to improve the quality of the k-Ga2O3 epitaxial thin film, ensuring a good adhesion to the diamond substrate, an optimal morphology, and a lower density of electrically active defects. This paves the way for the future development of novel hybrid architectures for UV and ionizing radiation detection, exploiting the unique features of gallium oxide and diamond as wide-bandgap semiconductors.

Materials (Basel) 17 (2), pp. 519

DOI: 10.3390/ma17020519

2024, Articolo in rivista, ENG

The synchronous detection technique for the accurate monitoring of high-energy pulsed X-rays

Stefano Salvatori, Sara Pettinato, Marco Girolami, Taras Kononenko, Victor Ralchenko, Maria Cristina Rossi

At high energy, the smaller inelastic nucleon-Carbon cross-section implies that diamond has a radiation hardness an order of magnitude higher than that of silicon. The production of high-quality diamond crystals and films grown using the chemical vapor deposition technique opened the way for the use of synthetic diamonds in the fabrication of detectors for charged particles and high-energy photons. More recently, laser-processing technology for the fabrication of three-dimensional contacts in diamond has been proposed to produce highly efficient detectors, even with ultra-low active volumes. However, buried-contact structures made with laser treatments unavoidably induce structural defects in the volume surrounding the buried columns, thus affecting the detector response due to trap-related charge transport mechanisms. When pulsed radiation is concerned, experimental results reported in this work demonstrate that synchronous signal conditioning can strongly mitigate the trap-mediated contribution, thereby improving the performance of the overall detection system. Significantly, these results pave the way for the application of diamond samples with three-dimensional buried-contacts in the development of detectors for accurate dosimetry.

Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment (Online) 1059, pp. 168954

DOI: 10.1016/j.nima.2023.168954

2024, Articolo in rivista, ENG

Perovskite solar cell technology scaling-up: Eco-efficient and industrially compatible sub-module manufacturing by fully ambient air slot-die/blade meniscus coating

Luigi Vesce, Maurizio Stefanelli, Federico Rossi, Luigi Angelo Castriotta, Riccardo Basosi, Maria Laura Parisi, Adalgisa Sinicropi, Aldo Di Carlo

The efficiency gap between perovskite (PVSK) solar sub-modules (size >=200 cm2) and lab scale cells (size ?1 cm2) is up to 36%. Moreover, the few attempts present in the literature used lab-scale techniques in a glove-box environment, reducing its compatibility for further product industrialization. Here, we report a PVSK sub-module (total area 320 cm2, aperture area 201 cm2, 93% geometrical fill factor [GFF]) fabricated in ambient air by hybrid meniscus coating techniques assisted by air and green antisolvent quenching method. To suppress nonradiative recombination losses, improve carrier extraction and control the PVSK growth on such a large surface, we adopted phenethylammonium iodide (PEAI) passivation and PVSK solvent addiction strategies. The high homogeneous and reproducible layers guarantee an efficiency of 16.13% (7% losses with respect to the small area cell and zero losses with respect to the mini-modules) and a stability of more than 3000 h according to International Summit on Organic PV Stability, dark storage/shelf life in ambient (ISOS-D-1). The sustainability of used methods and materials is demonstrated by the life cycle assessment. The scale-up operation allows for strong impact mitigation in all the environmental categories and more efficient consumption of the resources. Finally, the economic assessment shows a strong cost reduction scaling from mini- to sub-module (about 40%).

Progress in Photovoltaics: Research and Applications 32 (2), pp. 115–129

DOI: 10.1002/pip.3741

2023, Articolo in rivista, ENG

Low Dimension Elemental and van der Waals Hetetostructures Materials including C Nanostructures and Perovskites

Paola De Padova and Gurumurthy Hegde

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Nanomaterials and Nanotechnology 2023, pp. 9802519

DOI: 10.1155/2023/9802519

2023, Articolo in rivista, ENG

Recent Trends and Progress in Corrosion Inhibitors and Electrochemical Evaluation

Bijapur, K; Molahalli, V; Shetty, A; Toghan, A; De Padova, P; Hegde, G

Science and engineering research studies are currently concentrating on synthesizing, designing, producing, and consuming ecologically benign chemical species to replace harmful chemicals. This is due to the increasing demands of conservation knowledge and strict ecological regulations. Numerous environmentally friendly substitutes produced from natural resources, including biopolymers, plant extracts, chemical pharmaceuticals (drugs), and so on, are now frequently used as inhibitors to replace dangerous corrosion inhibitors. Many compounds have been extensively used. A range of methods, including physisorption, chemisorption, barrier protection, thin-film growth, and electrochemical procedures, will be used to provide corrosion resistance. The various kinds of corrosion inhibitors (CIs), the mechanisms underlying inhibition, and the evaluation procedures have all been covered in-depth. This review provides an overview of the relevant literature in which researchers and scientists used different types of CIs, the effect of CIs on metals, and information about designs and mechanisms used to minimize corrosion in a variety of equipment composed of alloys or metals, along with electrochemical evaluation studies. This review will provide scholars with fresh insights to advance the discipline.

Applied sciences 13 (18), pp. 10107

DOI: 10.3390/app131810107

2023, Articolo in rivista, ENG

A single resonance Regge pole dominates the forward-angle scattering of the state-to-state F+H2 -FH+H reaction at Etrans =62.09meV

Chengkui Xiahou, a J. N. L. Connor, *b Dario De Fazio c and Dmitri Sokolovski d e

The aim of the present paper is to bring clarity, through simplicity, to the important and long-standing problem: does a resonance contribute to the forward-angle scattering of the F + H2 reaction? We reduce the problem to its essentials and present a well-defined, yet rigorous and unambiguous, investigation of structure in the differential cross sections (DCSs) of the following three state-to-state reactionsatatranslationalenergyof62.09meV:F+H2(vi =0,ji =0,mi =0)-FH(vf =3,jf =0,1,2, mf = 0) + H, where vi, ji, mi and vf, jf, mf are the initial and final vibrational, rotational and helicity quantum numbers respectively. Firstly, we carry out quantum-scattering calculations for the Fu-Xu- Zhang potential energy surface, obtaining accurate numerical scattering matrix elements for indistin- guishable H2. The calculations use a time-independent method, with hyperspherical coordinates and an enhanced Numerov method. Secondly, the following theoretical techniques are employed to analyse structures in the DCSs: (a) full and Nearside-Farside (NF) partial wave series (PWS) and local angular momentum theory, including resummations of the full PWS up to second order. (b) The recently intro- duced ''CoroGlo'' test, which lets us distinguish between glory and corona scattering at forward angles for a Legendre PWS. (c) Six asymptotic (semiclassical) forward-angle glory theories and three asymptotic farside rainbow theories, valid for rainbows at sideward-scattering angles. (d) Complex angular momen- tum (CAM) theories of forward and backward scattering, with the Regge pole positions and residues computed by Thiele rational interpolation. Thirdly, our conclusions for the three PWS DCSs are: (a) the forward-angle peaks arise from glory scattering. (b) A broad (hidden) farside rainbow is present at side- ward angles. (c) A single Regge pole contributes to the DCS across the whole angular range, being most prominent at forward angles. This proves that a resonance contributes to the DCSs for the three transi- tions. (d) The diffraction oscillations in the DCSs arise from NF interference, in particular, interference between the Regge pole and direct subamplitudes.

PCCP. Physical chemistry chemical physics (Print) 26, pp. 3647–3666

DOI: 10.1039/d3cp04734b

2023, Articolo in rivista, ENG

Renormalized chemical kinetics and benchmark quantum mechanical rates: activation energies and tunnelling transitivities for the reactions of fluorine atoms with H2 and HD

Valter H. Carvalho-Silva1,2 · Flávio O. Sanches-Neto2,3,4 · Guilherme M. Leão1 · Simonetta Cavalli5 · Dario De Fazio6 · Maria C. Nucci7,8 · Vincenzo Aquilanti5,6

Experimental, theoretical and computational chemical kinetics contribute to progress both in molecular and materials sciences and in biochemistry, exploring the gap between elementary processes and complex systems. Stationary state quantum mechan- ics and statistical thermodynamics provide interpretive tools and instruments for classical molecular dynamics simulations for stable or metastable structures and near-equilibrium situations. Chemical reaction kinetics plays a key role at the mesoscales: time-dependent and evolution problems are typically tackled phenomenologically, and reactions through intermediates and transition states need be investigated and modelled. In this paper, scaling and renormalization procedures are developed beyond the Arrhenius equation and the Transition State Theory, regarding two key observables in reaction kinetics, the rate "constant" as a function of temperature (and its reciprocal, the generalised lifetime), and the apparent activation energy (and its reciprocal, the transitivity function). Coupled first-order equations--dependent on time and on temperature--are formulated in alterna- tive coupling scheme they link experimental results to effective modelling, or vice versa molecular dynamics simulations to predictions. The passage from thermal to tunnelling regimes is uniformly treated and applied to converged quantum mechanical calculations of rate constants available for the prototypical three-atom reactions of fluorine atoms with both H2 and HD: these are exothermic processes dominated by moderate tunnel, needing formal extension to cover the low-temperature regime where aspects of universal behaviour are shown to emerge. The results that have been validated towards experimental information in the 10-350 K temperature range, document the complexity of commonly considered "elementary" chemical reactions: they are relevant for modelling atmospheric and astrophysical environments. Perspectives are indicated of advances towards other types of transitions and to a global generality of processes of interest in applied chemical kinetics in biophysics and in astrochemistry.

Rendiconti lincei. Scienze fisiche e naturali 34, pp. 997–1011

DOI: 10.1007/s12210-023-01209-6

2023, Key note o lezione magistrale, ITA

Quantum reactive dynamics of elementary chemical processes: time indipendent vs wave-packets methods.

Dario De Fazio

In the last decades, development of new numerical methodologies for calculations of elementary chemical processes coupled with the fast increase of available computational resources, have allowed us to solve numerically quantum mechanical three body problems without introducing any approximation to the dynamics. Generally speaking, two main different approaches have been developed: time independent (most hyperspherical) and wave packets (time dependent) methods. Although the two different approaches should give of course the same results reproducing reactive observables (rate constants, integral and differential cross sections) the mathematical developments in the computational code make advantages and disadvantages of the two methods strongly correlated with the specific reactive phenomena under study so that, in feasible calculations, no all the processes of a system can be studied with both the methods. In the conference, I will show time independent [1-3] and wave packet [4] results for different processes of some prototypical chemical system obtained by me and my research groups, stressing potentiality and limits of the two methodologies used. References: [1] D. De Fazio, S. Cavalli and V. Aquilanti. 'Quantum dynamics and kinetics of the F + H2 and F + D2 reactions at low and ultra-low temperatures. Frontiers in Chemistry, 7 328 (2019). [2] D. De Fazio, S. Cavalli and V. Aquilanti. 'Benchmark Quantum Kinetics at Low Temperatures toward Absolute Zero and Role of Entrance Channel Wells on Tunneling, Virtual States, and Resonances: The F + HD Reaction'. J. Phys. Chem. A, 124 12 (2020). [3] D. De Fazio. 'The H + HeH+ --> He + H2+ reaction from the ultra-cold regime to the three-body breakup: exact quantum mechanical integral cross sections and rate constants'. Phys. Chem. Chem. Phys. 16 11662 (2014). [4] D. De Fazio, A. Aguado and C. Petrongolo. 'Non-adiabatic quantum dynamics of the dissociative charge transfer He+ + H2 --> He + H + H+'. Frontiers in Chemistry 7 249 (2019).

Cinetica Chimica alle micro, meso, bioscale. Chemical kinetics at micro-, meso-, bio-scales dedicated to Giangualberto Volpi (1928-2017), Accademia Nazionale dei Lincei. Roma (Italy), 27-28/3/2023

2023, Articolo in rivista, ENG

A membrane intercalating metal-free conjugated organic photosensitizer for bacterial photodynamic inactivation

Arianna Magni, Sara Mattiello, Luca Beverina, Giuseppe Mattioli, Matteo Moschetta, Anita Zucchi, Giuseppe Maria Paternò and Guglielmo Lanzani

Photodynamic inhibition (PDI) of bacteria represents a powerful strategy for dealing with multidrug- resistant pathogens and infections, as it exhibits minimal development of antibiotic resistance. The PDI action stems from the generation of a triplet state in the photosensitizer (PS), which subsequently transfers energy or electrons to molecular oxygen, resulting in the formation of reactive oxygen species (ROS). These ROS are then able to damage cells, eventually causing bacterial eradication. Enhancing the efficacy of PDI includes the introduction of heavy atoms to augment triplet generation in the PS, as well as membrane intercalation to circumvent the problem of the short lifetime of ROS. However, the former approach can pose safety and environmental concerns, while achieving stable membrane partitioning remains challenging due to the complex outer envelope of bacteria. Here, we introduce a novel PS, consisting of a metal-free donor-acceptor thiophene-based conjugate molecule (BV-1). It presents several advantageous features for achieving effective PDI, namely: (i) it exhibits strong light absorption due to the conjugated donor-acceptor moieties; (ii) it exhibits spontaneous and stable membrane partitioning thanks to its amphiphilicity, accompanied by a strong fluorescence turn-on; (iii) it undergoes metal-free intersystem crossing, which occurs preferentially when the molecule resides in the membrane. All these properties, which we rationalized via optical spectroscopies and calculations, current state-of-the-art treatments. Our approach holds significant potential for the development of new PS for controlling bacterial infections, particularly those caused by Gram-negative bacteria. enable the effective eradication of Escherichia coli, with an inhibition concentration that is below that of

Chemical science (Online) 14, pp. 8196–8205

DOI: 10.1039/d3sc01168b

2023, Contributo in atti di convegno, ENG

Ultrafast ionization of transparent materials under femtosecond laser irradiation

A. Abdelmalek, A. Sari, Z. Bedrane, M. Girolami

Electron plasma excited by direct femtosecond laser irradiation in diamond material has been investigated using Keldysh theory. The result shows that controlling the impact ionization process is a key factor to improve laser-induced nano-micromachining.

Laser Applications Conference 2023, Tacoma, Washington, United States of America, 8-12 ottobre 2023

DOI: 10.1364/ASSL.2023.JW2A.5

2023, Contributo in atti di convegno, ENG

Measuring the Ultrafast Dynamic of Nanoparticle Temperature on the fs-to-ps Time Scale

Bisio F., Ferrera M., Sygletou M., Magnozzi M., Catone D., O'keeffe P., Paladini A. , Toschi F., Benedetti S.,Pierantozzi G.M., Cucini R., Di Bona A.

The impulsive photoexcitation of nanoparticles kicks off the time-dependent re-equilibration of the electron gas, ion lattice, and environment. For better understanding and harnessing these processes, for thermoplasmonics or photocatalysis applications, it is paramount to know the dynamic, time-dependent evolution of the temperature of each system subcomponents. We report two different methods to directly deduce the temporal evolution of the electronic and lattice temperature of plasmonic Au nanoparticles excited by ultrashort laser pulses on the fs-ps time scale. © 2023, META Conference. All rights reserved.

Measuring the Ultrafast Dynamic of Nanoparticle Temperature on the fs-to-ps Time Scale, Paris, 18 July 2023 through 21 July 2023

2023, Rassegna della letteratura scientifica in rivista (Literature review), ENG

Impact of Structural Strain in Perovskite Epitaxial Thin Films on Their Functional Properties

Florin Andrei 1, Maria Dinescu 1 , Valentin Ion 1 , Floriana Craciun 2 , Ruxandra Birjega 1 and Nicu Doinel Scarisoreanu 1,*

The strain engineering effects induced by different means, e.g., the substrate lattice mismatch and/or chemical doping, on the functional properties of perovskite thin films have triggered interest in the use of these materials in different applications such as energy storage/generation or photonics. The effects of the film's thickness and strain state of the structure for the lead-free perovskite ferrite-based materials (BiFeO3-BFO; Y-doped BiFeO3-BYFO; LaFeO3-LFO) on their functional properties are highlighted here. As was previously demonstrated, the dielectric properties of BFO epitaxial thin films are strongly affected by the film thickness and by the epitaxial strain induced by the lattice mismatch between substrate and film. Doping the BiFeO3 ferroelectric perovskite with rare-earth elements or inducing a high level of structural deformation into the crystalline structure of LaFeO3 thin films have allowed the tuning of functional properties of these materials, such as dielectric, optical or photocatalytic ones. These changes are presented in relation to the appearance of complex ensembles of nanoscale phase/nanodomains within the epitaxial films due to strain engineering. However, it is a challenge to maintain the same level of epitaxial strain present in ultrathin films (<10 nm) and to preserve or tune the positive effects in films of thicknesses usually higher than 30 nm.

Crystals (Basel) 13, pp. 1686-1–1686-15

DOI: 10.3390/cryst13121686

2023, Articolo in rivista, ENG

Correlating nanoscale motion and ATP production in healthy and favism erythrocytes: a real-time nanomotion sensor study

M. Girasole (1), S. Dinarelli (1), G. Longo (1)

Red blood cells (RBCs) are among the simplest, yet physiologically relevant biological specimens, due to their peculiarities, such as their lack of nucleus and simplified metabolism. Indeed, erythrocytes can be seen as biochemical machines, capable of performing a limited number of metabolic pathways. Along the aging path, the cells' characteristics change as they accumulate oxidative and non-oxidative damages, and their structural and functional properties degrade. In this work, we have studied RBCs and the activation of their ATP- producing metabolism using a real-time nanomotion sensor. This device allowed time-resolved analyses of the activation of this biochemical pathway, measuring the characteristics and the timing of the response at different points of their aging and the differences observed in favism erythrocytes in terms of the cellular reactivity and resilience to aging. Favism is a genetic defect of erythrocytes, which affects their ability to respond to oxidative stresses but that also determines differences in the metabolic and structural characteristic of the cells. Our work shows that RBCs from favism patients exhibit a different response to the forced activation of the ATP synthesis compared to healthy cells. In particular, the favism cells, compared to healthy erythrocytes, show a greater resilience to the aging-related insults which was in good accord with the collected biochemical data on ATP consumption and reload. This surprisingly higher endurance against cell aging can be addressed to a special mechanism of metabolic regulation that permits lower energy consumption in environmental stress conditions.

Frontiers in microbiology 14 (1196764)

DOI: 10.3389/fmicb.2023.1196764

2023, Articolo in rivista, ENG

N-Heterocyclic Olefins on a Silicon Surface

Das, Mowpriya; Hogan, Conor; Zielinski, Robert; Kubicki, Milan; Koy, Maximilian; Kosbab, Canan; Brozzesi, Simone; Das, Ankita; Nehring, Mike Thomas; Balfanz, Viktoria; Brühne, Juls; Dähne, Mario; Franz, Martin; Esser, Norbert; Glorius, Frank

The adsorption of N-heterocyclic olefins (NHOs) on silicon is investigated in a combined scanning tunneling microscopy, X-ray photoelectron spectroscopy, and density functional theory study. We find that both of the studied NHOs bind covalently, with ylidic character, to the silicon adatoms of the substrate and exhibit good thermal stability. The adsorption geometry strongly depends on the N-substituents: for large N-substituents, an upright adsorption geometry is favored, while a flat-lying geometry is found for the NHO with smaller wingtips. These different geometries strongly influence the quality and properties of the obtained monolayers. The upright geometry leads to the formation of ordered monolayers, whereas the flat-lying NHOs yield a mostly disordered, but denser, monolayer. The obtained monolayers both show large work function reductions, as the higher density of the flat-lying monolayer is found to compensate for the smaller vertical dipole moments. Our findings offer new prospects in the design of tailor-made ligand structures in organic electronics and optoelectronics, catalysis, and material science.

Angewandte Chemie (Int. ed., Print) 62 (50), pp. e202314663

DOI: 10.1002/anie.202314663

2023, Articolo in rivista, ENG

Exploring the range of applicability of anisotropic optical detection in axially coordinated supramolecular structures

Goto, F.; Calloni, A.; Majumdar, I.; Yivlialin, R.; Filoni, C.; Hogan, C.; Palummo, M.; Biroli, A. Orbelli; Finazzi, M.; Duò, L.; Ciccacci, F.; Bussetti, G.

Ensuring the highest accuracy in determining the molecular assembling and the preservation of the chemical and physical properties of the molecules during the growth of organic layers requires a real-time monitoring of film formation. In this respect, optical techniques are preferred since they result in minimum organic film damage. Among these techniques, Reflectance Anisotropy Spectroscopy (RAS) proved to be the one with the highest sensitivity due to the development of intrinsic anisotropies in the optical response of molecular films, where molecular packing is driven by Van der Waals interactions. Recently, we proposed an original strategy to enable the growth of organic films via molecular self-assembly through highly directional coordination bonds. Herein, we consider a straightforward supramolecular structure employing axial bonds, based on the 1:1 assembly of a Co porphyrin (CoTPP) and a linear ligand (DPNDI). This system is characterized by a rather isotropic structure that might, in principle, result in a weak RAS signal. Therefore, in the present work, we critically assess the range of applicability of such a spectroscopy. A number of other surface science techniques, including Low Energy Electron Diffraction (LEED), photoemission spectroscopies (PES and IPES) and Atomic Force Microscopy (AFM) is employed to fully characterize the axially coordinated molecular film.

Inorganica Chimica Acta (Testo stamp.) 556, pp. 121612

DOI: 10.1016/j.ica.2023.121612

2023, Articolo in rivista, ENG

Energy-overlap of the Dirac surface state with bulk bands in SnBi2Te4

Eremeev, S. V.; De Luca, O.; Sheverdyaeva, P. M.; Ferrari, L.; Matetskiy, A. V.; Di Santo, G.; Petaccia, L.; Crovara, C.; Caruso, T.; Papagno, M.; Agostino, R. G.; Aliev, Z. S.; Moras, P.; Carbone, C.; Chulkov, E. V.; Pacilè, D.

Topological insulators in which the Fermi level is in the bulk gap and intersects only a topological surface state (the Dirac cone) are of special interest in the current research. In the last decades, a fine-tuning of the chemical composition of topological insulators has been carefully explored in order to control the Fermi level position with respect to the Dirac surface state. Taking the SnBi2Te4 crystal as a case study, we provide a characterization of its electronic structure by means of angle-resolved photoemission spectroscopy and first-principles calculations. We show that, going away from the Brillouin zone center, bulk band states energetically overlap with the Dirac cone at the Fermi level, thus providing an unwanted as well as hidden contribution to the transport properties of the material. In addition, the comparison between experimental results of the band structure with state-of-the-art simulations, implemented taking into account the number of defects, leads to useful insights on the existing limits in the description of this material.

Physical review materials (Online) 7 (1)

DOI: 10.1103/PhysRevMaterials.7.014203

2023, Articolo in rivista, ENG

Effect of Residual Carbon on Spin-Polarized Coupling at a Graphene/Ferromagnet Interface

Jugovac, Matteo; Cojocariu, Iulia; Genuzio, Francesca; Bigi, Chiara; Mondal, Debashis; Vobornik, Ivana; Fujii, Jun; Moras, Paolo; Feyer, Vitaliy; Locatelli, Andrea; Mente?, Tevfik Onur

Vertical stacks of graphene and ferromagnetic layers are predicted to be efficient spin filters, while the experimentally observed figures of merit systematically remain below the theoretical predictions. According to general consensus, a vaguely defined interface contamination is found responsible for this discrepancy. Here, it is demonstrated how the spin-polarized electronic structure of single-layer graphene supported on a ferromagnetic cobalt substrate is affected by the presence of an interfacial carbidic buffer layer, formed by residual carbon present in the Co substrate. It is found that the Co-C hybridized single-spin state near the Fermi level disappears upon thermal segregation of bulk carbon at the graphene-Co interface, which determines the electronic decoupling of graphene from the ferromagnetic support and consequently, the suppression of net spin polarization. These observations are shown to be independent of the graphene azimuthal orientation with respect to the high symmetry directions of the substrate. The findings provide clear evidence that the realization of highly polarized spin currents in graphene/ferromagnet heterostacks depends on careful control of the graphene growth process in order to eliminate interfacial carbon.

Advanced electronic materials

DOI: 10.1002/aelm.202300031

2023, Articolo in rivista, ENG

Facile Electron Transfer in Atomically Coupled Heterointerface for Accelerated Oxygen Evolution

Ibrahim, Kassa Belay; Shifa, Tofik Ahmed; Moras, Paolo; Moretti, Elisa; Vomiero, Alberto

An efficient and cost-effective approach for the development of advanced catalysts has been regarded as a sustainable way for green energy utilization. The general guideline to design active and efficient catalysts for oxygen evolution reaction (OER) is to achieve high intrinsic activity and the exposure of more density of the interfacial active sites. The heterointerface is one of the most attractive ways that plays a key role in electrochemical water oxidation. Herein, atomically cluster-based heterointerface catalysts with strong metal support interaction (SMSI) between WMnO and TiO are designed. In this case, the WMnO nanoflakes are uniformly decorated by TiO particles to create electronic effect on WMnO nanoflakes as confirmed by X-ray absorption near edge fine structure. As a result, the engineered heterointerface requires an OER onset overpotential as low as 200 mV versus reversible hydrogen electrode, which is stable for up to 30 h of test. The outstanding performance and long-term durability are due to SMSI, the exposure of interfacial active sites, and accelerated reaction kinetics. To confirm the synergistic interaction between WMnO and TiO, and the modification of the electronic structure, high-resolution transmission electron microscopy (HR-TEM), X-ray photoemission spectroscopy (XPS), and X-ray absorption spectroscopy (XAS) are used.

Small (Weinh., Print) 19 (1)

DOI: 10.1002/smll.202204765

2023, Articolo in rivista, ENG

Interfacing CrOx and CuS for synergistically enhanced water oxidation catalysis

Shifa, Tofik Ahmed; Gradone, Alessandro; Yusupov, Khabib; Ibrahim, Kassa Belay; Jugovac, Matteo; Sheverdyaeva, Polina Makarovna; Rosen, Johanna; Morandi, Vittorio; Moras, Paolo; Vomiero, Alberto

The sluggish kinetics associated with the oxygen evolution reaction (OER) limits the sustainability of fuel production and chemical synthesis. Developing catalysts based on Earth abundant elements with a reasonable strategy could solve the challenge. Here, we present a heterostructure built from CrOx and CuS whose interface gives rise to the advent of new functionalities in catalytic activity. Using X-ray photoelectron and absorption spectroscopies, we identified the multiple oxidation states and low coordination number of Cr metal in CrOx-CuS heterostructure. Benefitting from these features, CrOx-CuS generates oxygen gas through water splitting with a low over potential of 190 mV vs RHE at a current density of 10 mA cm. The catalyst shows no evident deactivation after a 36-hours operation in alkaline medium. The high catalytic activity, inspired by first principles calculations, and long-time durability make it one of the most effective OER electrocatalysts.

Chemical engineering journal ( Print) 453

DOI: 10.1016/j.cej.2022.139781

2023, Articolo in rivista, ENG

MoS2 Nanosheets Uniformly Anchored on NiMoO4 Nanorods, a Highly Active Hierarchical Nanostructure Catalyst for OER and Pseudo-Capacitors

Solomon, Getachew; Kohan, Mojtaba Gilzad; Mazzaro, Raffaello; Jugovac, Matteo; Moras, Paolo; Morandi, Vittorio; Concina, Isabella; Vomiero, Alberto

Hierarchical nanostructures have attracted considerable research attention due to their applications in the catalysis field. Herein, we design a versatile hierarchical nanostructure composed of NiMoO nanorods surrounded by active MoS nanosheets on an interconnected nickel foam substrate. The as-prepared nanostructure exhibits excellent oxygen evolution reaction performance, producing a current density of 10 mA cm at an overpotential of 90 mV, in comparison with 220 mV necessary to reach a similar current density for NiMoO. This behavior originates from the structural/morphological properties of the MoS nanosheets, which present numerous surface-active sites and allow good contact with the electrolyte. Besides, the structures can effectively store charges, due to their unique branched network providing accessible active surface area, which facilitates intermediates adsorptions. Particularly, NiMoO/MoS shows a charge capacity of 358 mAhg at a current of 0.5 A g (230 mAhg for NiMoO), thus suggesting promising applications for charge-storing devices.

Advanced sustainable systems 7 (2)

DOI: 10.1002/adsu.202200410

InstituteSelected 1/199

ISM, Istituto di struttura della materia

    ISTI, Istituto di scienza e tecnologie dell'informazione "Alessandro Faedo" (16395)
    ISPC, Istituto di Scienze del Patrimonio Culturale (9564)
    IFC, Istituto di fisiologia clinica (7773)
    ISMAR, Istituto di scienze marine (7664)
    ISAC, Istituto di scienze dell'atmosfera e del clima (7466)
    IRPI, Istituto di ricerca per la protezione idrogeologica (7354)
    IGAG, Istituto di geologia ambientale e geoingegneria (7114)
    ICMATE, Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia (6874)
    ISPA, Istituto di scienze delle produzioni alimentari (6576)
    ICB, Istituto di chimica biomolecolare (6479)
AuthorSelected 0/661
    Avaldi Lorenzo (248)
    Coreno Marcello (209)
    Bolognesi Paola (205)
    Cricenti Antonio (196)
    Agostinelli Elisabetta (160)
    Varvaro Gaspare (160)
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    Testa Alberto Maria (146)
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    MD.P06.006.001, Microscopia a Scansione a Sonda Locale su sistemi nanostrutturati e materiali biologici (304)
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