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Photoactive materials based on semiconducting nanocarbons——A challenge opening new possibilities for photocatalysis

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Journal of Energy Chemistry 2017年第2期26卷 207-218页

作者： Siglinda Perathoner Claudio Ampelli Shiming Chen Rosalba Passalacqua Dangsheng Su Gabriele Centi Dept.s mift and ChiBioFarAm Section Industrial ChemistryUniversity of MessinaINSTM/CASPE and ERIC aisbl Dalian Institute of Chemical Physics Chinese Academy of Sciences

This perspective paper introduces the concept that nanocarbons and related materials such as carbon dots are an interesting intrinsic photocatalytic semiconducting material, and not only a modifier of the existing (semiconducting) materials to prepare hybrid materials. The semiconducting properties of the nanocarbons, and the possibility to have the band gap within the visible-light region through defect band engineering, introduction of light heteroatoms and control/manipulation of the curvature or surface functionalization are discussed. These materials are conceptually different from the 'classical' semiconducting photocatalysts, because semiconductor domains with tuneable characteristics are embedded in a conductive carbon matrix, with the presence of various functional groups (as C=0 groups) enhancing charge separation by trapping electrons. These nanocarbons open a range of new possibilities for photocatalysis both for energetic and environmental applications. The use of nanocarbons as quantum dots and photo luminescent materials was also analysed. (C) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

关键词： Nanocarbon Carbon-type photocatalysts Semiconducting nanocarbons Carbon nano-dots Water splitting CO2 photoreduction

Centralizers of X-Generalized Skew Derivations on Multilinear Polynomials in Prime Rings

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Communications in Mathematics and Statistics 2018年第1期6卷 49-71页

作者： Vincenzo De Filippis Feng Wei mift University of Messina98166 MessinaItaly School of Mathematics and Statistics Beijing Institute of TechnologyBeijing 100081People’s Republic of China

Let R be a prime ring of characteristic different from 2,Q_(r) be its right MartindalequotientringandC beitsextendedcentroid,G beanonzero X-generalized skew derivation of R,and S be the set of the evaluations of a multilinear polynomial f(x_(1),...,x_(n))over C with n non-commuting *** u,v∈R be such that uG(x)x+G(x)xv=0 for all x∈*** one of the following statements holds:(a)v∈C and there exist a,b,c∈Q_(r) such that G(x)=ax+bxc for any x∈R with(u+v)a=(u+v)b=0;(b)f(x_(1),...,x_(n))2 is central-valued on R and there exists a∈Q r such that G(x)=ax for all x∈R with ua+av=0.

关键词： X-Generalized skew derivation Multilinear polynomial Prime ring

Etherification of HMF to biodiesel additives: The role of NH4+ confinement in Beta zeolites

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Journal of Energy Chemistry 2019年第9期28卷 114-121页

作者： Paola Lanzafame Georgia Papanikolaou Katia Barbera Gabriele Centi Siglinda Perathoner Departments of ChiBioFarAm and mift-Section of Industrial Chemistry University of Messina ERIC aisbl and CASPE-INSTM

The role of NH4^+ ion confinement in the catalytic etherification of HMF(5-hydroxymethylfurfural) with ethanol to biodiesel additives was evidenced by studying the catalytic behavior of NH4^+-Beta zeolites with SiO2/Al2O3 ratios of 25 and *** order to affect the strength and distribution of the acidic sites, as well as the mobility of NH4^+ ions in the zeolites cages, a secondary level of porosity was introduced in the NH4^+-Beta, presenting a different stability versus alkaline treatment, by using a thermal or an ultrasound assisted *** analyzing the catalytic behavior in these two series of samples with respect to the changes in porosity by nonlocal density functional theory, structure by XRD, amount of acid sites by FT-IR and mobility of NH4^+ cations by measurements of reversible NH4^+ exchange capacity, was evidenced a decrease in catalytic performances both in terms of rate of HMF depletion and productivity to the main products, when confinement of the ammonium ions is lost due to the introduction of *** high capability of ammonium ions release, associated to the mono-dentate configuration,and the minor confinement effect inside the zeolite pore system, due to the more opened pores structure of mesoporous zeolites, hinders both the direct etherification of HMF to EMF [5-(ethoxymethyl)furan-2-carbaldehyde] and the parallel reaction pathway via acetalization, favoring the rapid desorption of the HMFDEA [5-(hydroxymethyl)furfural diethyl acetal] product out of the crystal and the consequent inhibition of the consecutive reactions to EMFDEA [5-(ethoxymethyl)furfural diethyl acetal] and EMF.

关键词： Ammonium ion Beta zeolite HMF etherification Confinement effect 5-(ethoxymethyl)furan-2-carbaldehyde

UV and soft x-ray emission from gaseous and solid targets employing SiC detectors

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Plasma Science and Technology 2021年第5期23卷 147-154页

作者： Alfio TORRISI Przemysław WACHULAK Lorenzo TORRISI CEDAD-Dept.of Mathematics and Physics‘E.De Giorgi’ University of SalentoLecce 73100Italy Institute of Optoelectronics Military University of TechnologyWarsaw 00-908Poland Dept.of Mathematical and Computer Sciences Physical Sciences and Earth Sciences(MIFT)-University of MessinaMessina 98166Italy

A ns Nd:YAG pulsed laser has been employed to produce plasma from the interaction with a dense target,generating continuum and UV and soft x-ray emission depending on the laser parameters and target *** laser hits solid and gaseous targets producing plasma in high vacuum,which was investigated by employing a silicon carbide *** two different interaction mechanisms were studied,as well as their dependence on the atomic *** photon emission from laser-generated plasma produced by solid targets,such as boron nitride(BN)and other elements(Al,Cu,Sn and Ta)and compounds such as polyethylene,has been compared with that coming from plasma produced by irradiating different gas-puff targets based on N_(2)and other gases(Ar,Xe,Kr,SF_(6)).The experimental results demonstrated that the yields are comparable and,in both cases,increase proportionally to the target atomic *** obtained results,focusing the attention on the advantages and drawbacks of the employed targets,are presented and discussed.

关键词： laser-matter interaction plasma diagnostics SiC detectors

A study of the hydrogen bonds effect on the water density and the liquid-liquid transition

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Science China(Physics,Mechanics & Astronomy) 2019年第10期62卷 24-32页

作者： Francesco Mallamace Carmelo Corsaro Enza Fazio Sow-Hsin Chen Domenico Mallamace Department of Nuclear Science and Engineering Massachusetts Institute of TechnologyCambridge MA 02139USA Center for Polymer Studies and Department of Physics Boston UniversityBoston MA 02215USA Dipartimento di Scienze Matematiche e Informatiche Scienze Fisiche e Scienze della Terra(MIFT)Universita di MessinaMessina 98166Italy

We study the hydrogen bonds effect on the water density as a function of temperature and pressure from the supercritical region to the metastable supercooled and amorphous phases. We identify two important thermodynamic thresholds, that is P~*■2 kbar and T~*■315 K, that separate two different water behaviors in terms of hydrogen bonding capability. For T < T~* and P < P~* the formation and stability of hydrogen bonded local structures are enhanced. The additional analyses of the proton NMR chemical shift and of the relaxation time confirm this evidence and highlight the structure breaking effects of the pressure. The investigation of both structural and dynamical quantities allow us to draw a complete picture of the water properties in terms of the temperaturepressure dependence of hydrogen bonding.

关键词： water hydrogen bond density critical supercooled phase

Hydrophilic and hydrophobic competition in water-methanol solutions

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Science China(Physics,Mechanics & Astronomy) 2019年第10期62卷 8-15页

作者： Domenico Mallamace Sow-Hsin Chen Carmelo Corsaro Enza Fazio Francesco Mallamace HEugene Stanley Dipartimento mift Universita di MessinaMessina 1-98166Italy Department of Nuclear Science and Engineering Massachusetts Institute of TechnologyCambridge MA 02139USA Istituto dei Sistemi Complessi(ISC)-CNR Rome 00185Italy Center for Polymer Studies and Department of Physics Boston UniversityBoston MA 02215USA

We study the thermal behavior of the longitudinal spin-lattice, T1, and the transverse spin-spin, T2, relaxation times of the macroscopic magnetization in water/methanol solutions. Our aim is to investigate the reciprocal influence of hydrophobic effects on water properties and of hydrophilicity（via hydrogen bond, HB, interactions） on the solute. Using classical Nuclear Magnetic Resonance spectroscopy, we find a single characteristic correlation time τcthat reflects all local structural configurations and characterizes the thermal motion effects of the magnetic nuclei on the spin-spin interaction. We find that in the supercooled regime the correlations are stronger, with respect to ambient temperature, because the HB interactions have a lifetime long enough to sustain a stable water network. However, increasing the temperature, progressively decreases the HB interaction lifetime and destroys the water clusters with a consequent decoupling in the dynamic modes of the system. In addition, at temperatures higher than about 265 K, the hydrophobicity becomes gradually stronger and governs the physical properties of the solutions.

关键词： hydrophobic-hydrophilic interactions water systems thermal properties

Enhanced performance in the direct electrocatalytic synthesis of ammonia from N2 and H2O by an in-situ electrochemical activation of CNT-supported iron oxide nanoparticles

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能源化学：英文版 2020年第10期29卷 22-32页

作者： Shiming Chen Siglinda Perathoner Claudio Ampelli Hua Wei Salvatore Abate Bingsen Zhang Gabriele Centi Dept.ChimBioFarAM 98166 MessinaItaly Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023LiaoningChina Catalysis and Materials Division Institute of Metal ResearchChinese Academy of Sciences(IMR CAS)Shenyang Dept.mift(Industrial University of Messina ERIC aisbl and INSTM/CASPE98166 MessinaItaly

The direct electrocatalytic synthesis of ammonia from N2 and H2O by using renewable energy sources and ambient pressure/temperature operations is a breakthrough technology,which can reduce by over 90%the greenhouse gas emissions of this chemical and energy storage *** report here an in-situ electrochemical activation method to prepare Fe2O3-CNT(iron oxide on carbon nanotubes)electrocatalysts for the direct ammonia synthesis from N2 and *** in-situ electrochemical activation leads to a large increase of the ammonia formation rate and Faradaic efficiency which reach the surprising high values of 41.6μg mgcat^−1 h^−1 and 17%,respectively,for an in-situ activation of 3 h,among the highest values reported so far for non-precious metal catalysts that use a continuous-flow polymer-electrolytemembrane cell and gas-phase operations for the ammonia synthesis *** electrocatalyst was stable at least 12 h at the working *** by switching N2 to Ar evidence that ammonia was formed from the gas-phase *** analysis of the changes of reactivity and of the electrocatalyst characteristics as a function of the time of activation indicates a linear relationship between the ammonia formation rate and a specific XPS(X-ray-photoelectron spectroscopy)oxygen signal related to O2−in iron-oxide *** results together with characterization data by TEM and XRD suggest that the iron species active in the direct and selective synthesis of ammonia is a maghemite-type iron oxide,and this transformation from the initial hematite is responsible for the in-situ enhancement of 3-4 times of the TOF(turnover frequency)and NH3 Faradaic *** transformation is likely related to the stabilization of the maghemite species at CNT defect sites,although for longer times of preactivation a sintering occurs with a loss of performances.

关键词： Ammonia direct synthesis Electrochemical activation Heterogeneous catalysis Active sites N2 electrocatalytic conversion

Smart catalytic materials for energy transition

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SmartMat 2020年第1期1卷 1-3页

作者： Gabriele Centi Department of mift University of MessinaMessinaItaly ERIC aisbl BruxellesBelgium School of Chemical Engineering and Technology Tianjin UniversityChina

Energy transition,and the related chemistry transition due to their strong nexus,is creating a major worldwide change in the current production system,driven initially by social and environmental pressures(cleaner production,reduced greenhouse gas emissions),but today instead is pushed by economic(renewable energy sources are becoming progressively the more economic energy form)and geopolitical(energy security)*** and natural gases are the building blocks of the current refinery and(petro)chemistry,but going beyond fossil fuels is the challenge associated with this *** has also major implications on the technologies and processes actually in use,further pushed from another emerging direction associated with the progressive change from centralized to delocalized productions,for a better link with the territory and the local *** combined effect of these two emerging directions determines a radical change in the energy and chemical production systems,with major technological *** process technologies in the area of chemical and fuel production cannot just be adapted,they need to be fully redesigned(also in terms of concepts,materials,engineering)to address the new challenges of using renewable energy sources in delocalized productions(small‐scale production at the regional level using local resources and in strong symbiosis to other local productions).

关键词： energy transition photoresponsive adsorbents self‐regenerative catalysts smart catalysts REFERENCES

Experimental tests for a liquid-liquid critical point in water

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Science China(Physics,Mechanics & Astronomy) 2020年第12期63卷 30-71页

作者： Domenico Mallamace Carmelo Corsaro Francesco Mallamace H.Eugene Stanley Department ChiBioFarAm(Industrial Chemistry) University of MessinaERIC and CASPE/INSTMMessina 98166Italy Dipartimento mift Universitàdi MessinaMessina 98166Italy Department of Nuclear Science and Engineering Massachusetts Institute of TechnologyCambridge MA 02139USA Istituto dei Sistemi Complessi(ISC)-CNR Rome 00185Italy Center for Polymer Studies and Department of Physics Boston UniversityBoston MA 02215USA

Water is a fascinating *** composition is simple—one oxygen and two hydrogen atoms—but its chemistry and physics are extremely complex and exhibit 75 documented *** these anomalies and their molecular origin are not completely understood,we know that hydrogen bonds play key roles in all of the phases of ***,there is experimental evidence that the polymorphism of the ice structure extends into the liquid phase and is associated with a liquid-liquid coexistence *** is currently a topic of great interest in water research because there are indications that the end point of the coexistence line corresponds to a second critical point inside the supercooled liquid *** examine the recent progress in understanding water anomalies and the liquid-liquid phase transition hypothesis,including the results of recent experimental work and molecular simulations of both bulk and confined *** examine experimental results that test whether the behavior of liquid water is consistent with the"liquid polymorphism"hypothesis that liquid water can exist in two distinct phases of differing *** also examine recent research on the anomalies of nanoconfined water and,in particular,on water in biological *** find that the concept of liquid polymorphism can also describe the properties of other liquids that have two characteristic length scales.

关键词： hydrophobic-hydrophilic interactions water systems thermal properties