Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)proc...Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)procedure.This can be very important in defense-related applications,where optimum performance needs to be guaranteed.The quality of the Polyetherimide 3D-P specimens was examined by considering six control parameters,namely,infill percentage,layer height,deposition angle,travel speed,nozzle,and bed temperature.The quality indicators were the root mean square(Rq)and average(Ra)roughness,porosity,and the actual to nominal dimensional deviation.The examination was performed with optical profilometry,optical microscopy,and micro-computed tomography scanning.The Taguchi design of experiments was applied,with twenty-five runs,five levels for each control parameter,on five replicas.Two additional confirmation runs were conducted,to ensure reliability.Prediction equations were constructed to express the quality indicators in terms of the control parameters.Three modeling approaches were applied to the experimental data,to compare their efficiency,i.e.,Linear Regression Model(LRM),Reduced Quadratic Regression Model,and Quadratic Regression Model(QRM).QRM was the most accurate one,still the differences were not high even considering the simpler LRM model.展开更多
This paper reports the fabrication of Nb thin films through pulsed laser deposition at different substrate temperatures, ranging from 300 to 660 K. While the variation of the substrate temperature does not affect sign...This paper reports the fabrication of Nb thin films through pulsed laser deposition at different substrate temperatures, ranging from 300 to 660 K. While the variation of the substrate temperature does not affect significantly the excellent Nb thin film adhesion to the Si（100） substrate surface, the increase of the substrate temperature up to 570 K promotes an improvement of the grown film in terms of morphology and roughness. Such improvement is achieved through the formation of wider columnar structures with a reduced superficial roughness, around 5 nm, as shown by scanning electron microscopy（SEM） and atomic force microscopy. The use of temperatures over 570 K increases the substrate roughness due to the formation of irregular structures inside the film, as observed by SEM cross section analysis, and does not produce a relevant improvement on the crystalline structure of the material.展开更多
We present a novel approach for tailoring the laser induced surface topography upon femtosecond(fs)pulsed laser irradiation.The method employs spatially controlled double fs laser pulses to actively regulate the hydro...We present a novel approach for tailoring the laser induced surface topography upon femtosecond(fs)pulsed laser irradiation.The method employs spatially controlled double fs laser pulses to actively regulate the hydrodynamic microfluidic motion of the melted layer that gives rise to the structures formation.The pulse train used,in particular,consists of a previously unexplored spatiotemporal intensity combination including one pulse with Gaussian and another with periodically modulated intensity distribution created by Direct Laser Interference Patterning(DLIP).The interpulse delay is appropriately chosen to reveal the contribution of the microfluidic melt flow,while it is found that the sequence of the Gaussian and DLIP pulses remarkably influences the surface profile attained.Results also demonstrate that both the spatial intensity of the double pulse and the effective number of pulses per irradiation spot can further be modulated to control the formation of complex surface morphologies.The underlying physical processes behind the complex patterns’generation were interpreted in terms of a multiscale model combining electron excitation with melt hydrodynamics.We believe that this work can constitute a significant step forward towards producing laser induced surface structures on demand by tailoring the melt microfluidic phenomena.展开更多
Despite that organic-inorganic lead halide perovskites have attracted enormous scientific attention for energy conversion applications over the recent years,the influence of temperature and the type of the employed ho...Despite that organic-inorganic lead halide perovskites have attracted enormous scientific attention for energy conversion applications over the recent years,the influence of temperature and the type of the employed hole transport layer(HTL)on the charge carrier dynamics and recombination processes in perovskite photovoltaic devices is still largely unexplored.In particular,significant knowledge is missing on how these crucial parameters for radiative and non-radiative recombinations,as well as for efficient charge extraction vary among different perovskite crystalline phases that are induced by temperature variation.Herein,we perform micro photoluminescence(pPL)and ultrafast time resolved transient absorption spectroscopy(TAS)in Glass/Perovskite and two dierent Glass/ITO/HTL/Perovskite configurations at temperatures below room temperature,in order to probe the charge carrier dynamics of different perovskite crystalline phases,while considering also the effect of the employed HTL polymer.Namely,CH_(3)NH_(3)Pbb films were deposited on Glass,PEDOT:PSS and PTAA polymers,and the developed Glass/CH_(3)NH_(3)PbI_(3)and Glass/ITO/HTL/CH_(3)NH_(3)PbI_(3)architectures were studied from 85 K up to 215 K in order to explore the charge extraction dynamics of the CH_(3)NH_(3)PbI_(3)orthorhombic and tetragonal crystalline phases.It is observed an unusual blueshift of the bandgap with temperature and the dual emission at temperature below of 100 K and also,that the charge carrier dynamics,as expressed by hole injection times and free carrier recombination rates,are strongly depended on the actual pervoskite crystal phase,as well as,from the selected hole transport material.展开更多
Femtosecond pulsed lasers have been widely used over the past decades due to their capability to fabricate precise patterns at the micro-and nano-lengths scales. A key issue for efficient material processing is the de...Femtosecond pulsed lasers have been widely used over the past decades due to their capability to fabricate precise patterns at the micro-and nano-lengths scales. A key issue for efficient material processing is the determination of the laser parameters used in the experimental set ups. Despite a systematic investigation that has been performed to highlight the impact of every parameter independently, little attention has been drawn on the role of the substrate material on which the irradiated solid is placed. In this work, the influence of the substrate is emphasised for films of various thicknesses, which demonstrates that both the optical and thermophysical properties of the substrate affect the thermal fingerprint on the irradiated film while the impact is manifested to be higher at smaller film sizes. Two representative materials, silicon and fused silica, have been selected as typical substrates for thin films(gold and nickel) of different optical and thermophysical behaviour and the thermal response and damage thresholds are evaluated for the irradiated solids. The pronounced influence of the substrate is aimed to pave the way for new and more optimised designs of laserbased fabrication set ups and processing schemes.展开更多
By using a first-principles approach,monolayer PbI_(2)is found to have great potential in thermoelectric applications.The linear Boltzmann transport equation is applied to obtain the perturbation to the electron distr...By using a first-principles approach,monolayer PbI_(2)is found to have great potential in thermoelectric applications.The linear Boltzmann transport equation is applied to obtain the perturbation to the electron distribution by different scattering mechanisms.The mobility is mainly limited by the deformation-potential interaction with long-wavelength acoustic vibrations at low carrier concentrations.At high concentrations,ionized impurity scattering becomes stronger.The electrical conductivity and Seebeck coefficient are calculated accurately over various ranges of temperature and carrier concentration.The lattice thermal conductivity of PbI_(2),0.065 W m^(−1)K^(−1)at 300 K,is the lowest among other 2D thermoelectric materials.Such ultralow thermal conductivity is attributed to large atomic mass,weak interatomic bonding,strong anharmonicity,and localized vibrations in which the vast majority of heat is trapped.These electrical and phonon transport properties enable a high thermoelectric figure of merit over 1 for both p-type and n-type doping from 300 K to 900 K.A maximum zT of 4.9 is achieved at 900 K with an electron concentration of 1.9×10^(12)cm^(−2).Our work shows exceptionally good thermoelectric energy conversion efficiency in monolayer PbI_(2),which can be integrated to the existing photovoltaic devices.展开更多
Metal halide perovskites stand at the nexus of materials innovation,nanoscale engineering,and real-world device integration.Their journey from laboratory curiosities to contenders for commercial photovoltaics,radiatio...Metal halide perovskites stand at the nexus of materials innovation,nanoscale engineering,and real-world device integration.Their journey from laboratory curiosities to contenders for commercial photovoltaics,radiation detectors,and photocatalytic systems has been propelled not only by exceptional optoelectronic properties—but decisively,by how they are fabricated,structured,and interfaced.This Special Issue of Light:Advanced Manufacturing,titled“Perovskite Nanomaterials and Nanostructures Fabrication for Photonics and Optoelectronics”,showcases a new generation of research where synthesis,nanostructuring,and interfacial control converge to solve long-standing challenges:instability in operational environments,poor reproducibility,scalability bottlenecks,and performance ceilings.展开更多
Photocatalytic water splitting technology can directly convert solar energy into H_(2) via a zero-carbon route,offering a sustainable solution for solar utilization and H_(2) supply.Among various developed photocataly...Photocatalytic water splitting technology can directly convert solar energy into H_(2) via a zero-carbon route,offering a sustainable solution for solar utilization and H_(2) supply.Among various developed photocatalysts,Z-scheme heterojunction mimicking natural photosynthesis by combining two dissimilar semiconductors for redox reactions in series has unequivocally demonstrated its superiority in enhanced charge transfer,robust redox driving force,and wide optical absorption range.A comprehensive understanding on the fundamental principles of interface engineering between semiconductor components is the key to construct an efficient Z-scheme heterojunction.By focusing on different types of semiconductors,this article thoroughly expounds the coupling principles of components in binary mediator-free and ternary solid-mediator Z-scheme heterojunctions for photocatalytic water splitting,from the viewpoint of band structure alignment and interfacial electric field design.In addition to the well summarized research progresses in recent years,perspectives on the challenges and opportunities for developing advanced Z-scheme heterojunctions are provided.展开更多
The photocatalytic oxidation of gaseous benzene,toluene and xylene(BTX)over un-doped,0.1 and 1 wt%Mn-TiO_(2)nanoparticles under ultraviolet and visible irradiation was studied in atmosphere of synthetic air or inert g...The photocatalytic oxidation of gaseous benzene,toluene and xylene(BTX)over un-doped,0.1 and 1 wt%Mn-TiO_(2)nanoparticles under ultraviolet and visible irradiation was studied in atmosphere of synthetic air or inert gas.The photocatalytic decomposition efficiency and the oxidation products were determined using a Static Photochemical Reactor coupled with FTIR spectroscopy.BTX underwent efficient decomposition over Mn-TiO_(2)photocatalysts under UV irradiation,more with oxygen presence and less without oxygen.More important toluene and xylene went substantial decomposition over 0.1 mol%Mn-TiO_(2)under visible irradiation with oxygen presence.The main final oxidation products in the UV photocatalysis of BTX were CO_(2),CO and H2O,with CO_(2) and CO yields 4 and 2 respectively.The conversion percentage of benzene,toluene,and xylene to CO_(2) were 63.6%,56.4%,51.8%,and to CO 29%,26.5%,23.2%,respectively.In the visible photocatalysis of toluene and xylene the yields of CO were insignificant.Formation of carbon containing deposits on TiO_(2)surfaces was observed after extensive UV photocatalysis of toluene and xylene,and such by-products surface coverage may reduce the photocatalytic activity of TiO_(2)samples.Some aspects of the photocatalytic mechanism were examined.展开更多
Strong terahertz(THz)electric and magnetic transients open up new horizons in science and applications.We review the most promising way of achieving sub-cycle THz pulses with extreme field strengths.During the nonline...Strong terahertz(THz)electric and magnetic transients open up new horizons in science and applications.We review the most promising way of achieving sub-cycle THz pulses with extreme field strengths.During the nonlinear propagation of two-color mid-infrared and far-infrared ultrashort laser pulses,long,and thick plasma strings are produced,where strong photocurrents result in intense THz transients.The corresponding THz electric and magnetic field strengths can potentially reach the gigavolt per centimeter and kilotesla levels,respectively.The intensities of these THz fields enable extreme nonlinear optics and relativistic physics.We offer a comprehensive review,starting from the microscopic physical processes of light-matter interactions with mid-infrared and far-infrared ultrashort laser pulses,the theoretical and numerical advances in the nonlinear propagation of these laser fields,and the most important experimental demonstrations to date.展开更多
We herein present a simple,fast,low-temperature,post-glass melting fabrication protocol in which a photochromic silver cation based modified zone is incorporated within silver metaphosphate glass(AgPO_(3)).The selecti...We herein present a simple,fast,low-temperature,post-glass melting fabrication protocol in which a photochromic silver cation based modified zone is incorporated within silver metaphosphate glass(AgPO_(3)).The selection of AgPO_(3)glass is mainly based on its relative“soft”nature(T_(g)=192℃)that enables the integration of silver cations from the surface deposited AgCl layer,while being transparent in most of the visible range,and therefore suitable for smart photochromic window applications.The suggested synthesis procedure permits the controlled formation of a silver cation modified layer within the host glass matrix,while the characteristics of the layer itself can be adjusted correspondingly.Our findings reveal a direct relationship between the developed composite AgCleAgPO_(3)glass photochromic response and the morphological features of the integrated layer,i.e.,thickness and position.More importantly,the photochromic response time with various UV irradiation doses is also studied,where remarkable response times of several seconds are obtained.Processes and efforts to further enhance the photochromic performance by utilizing the presence of silver nanoparticles within the glass matrix are also presented and discussed.展开更多
Highly-sensitive and stable ozone and hydrogen sensing elements were fabricated based on well-crystalline rounded cube-shaped CsPbBr 3 microcrystals,synthesized by a facile solution process per-formed under ambient co...Highly-sensitive and stable ozone and hydrogen sensing elements were fabricated based on well-crystalline rounded cube-shaped CsPbBr 3 microcrystals,synthesized by a facile solution process per-formed under ambient conditions.It is shown that such elements demonstrate enhanced room tem-perature gas sensing ability compared to the previously reported metal halide and oxide-based ones.Electrical measurements performed on these sensing components revealed high sensitivity to ultra-low ozone and hydrogen concentrations,namely 4 ppb and 1 ppm respectively,as well as a remarkable repeatability,even after a few months of storage in ambient conditions.Both ozone and hydrogen sensors were self-activated,as they did not require the use of UV or heating external stimuli to operate,and exhibited fast detection and short restoration times.All such attractive properties along with the simple fabrication process could provide an easy,efficient and low-cost technology for the realization of future gas sensing devices.展开更多
In this White Paper we present the potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies related to Observatory Science targets. These include flaring stars, supernova remnants, accreting wh...In this White Paper we present the potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies related to Observatory Science targets. These include flaring stars, supernova remnants, accreting white dwarfs, low and high mass X-ray binaries, radio quiet and radio loud active galactic nuclei, tidal disruption events, and gamma-ray bursts. eXTP will be excellently suited to study one common aspect of these objects: their often transient nature. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Science, the eXTP mission is expected to be launched in the mid 2020s.展开更多
Hydrogen halide gases are one of the most wide‐spread pollutants of atmosphere,which are generated by various industrial sectors or natural processes,and may dramatically affect human health above certain thresholds ...Hydrogen halide gases are one of the most wide‐spread pollutants of atmosphere,which are generated by various industrial sectors or natural processes,and may dramatically affect human health above certain thresholds of exposure.Hence,it is critically important to develop effective sensing methods for these gases.Herein,we review the recent progress as well as fundamental mechanisms,materials,and designs for the hydrogen halide gas sensors.We discuss in detail four major types of sensors:acoustic,chemical,optical,and the emerging nanophotonic sensors,categorizing them based on their operation principles.Acoustic sensors are discussed with a focus on microbalance‐based and surface acoustic wave gas sensors.Chemical sensors are considered from the point of view of electrochemical and chemiresistive sensing mechanisms.Optical sensors are analyzed,covering fluorescence‐based optical sensors,laser absorption‐based techniques,photoacoustic spectroscopy,and nonlinear optical methods.Finally,emerging nanophotonic sensors are introduced,emphasizing plasmonic and all‐dielectric nanophotonic approaches.We offer insights into the key operation mech-anisms of different types of sensors for hydrogen halide gases and provide their direct comparison.展开更多
文摘Additive Manufacturing(AM)can provide customized parts that conventional techniques fail to deliver.One important parameter in AM is the quality of the parts,as a result of the material extrusion 3D printing(3D-P)procedure.This can be very important in defense-related applications,where optimum performance needs to be guaranteed.The quality of the Polyetherimide 3D-P specimens was examined by considering six control parameters,namely,infill percentage,layer height,deposition angle,travel speed,nozzle,and bed temperature.The quality indicators were the root mean square(Rq)and average(Ra)roughness,porosity,and the actual to nominal dimensional deviation.The examination was performed with optical profilometry,optical microscopy,and micro-computed tomography scanning.The Taguchi design of experiments was applied,with twenty-five runs,five levels for each control parameter,on five replicas.Two additional confirmation runs were conducted,to ensure reliability.Prediction equations were constructed to express the quality indicators in terms of the control parameters.Three modeling approaches were applied to the experimental data,to compare their efficiency,i.e.,Linear Regression Model(LRM),Reduced Quadratic Regression Model,and Quadratic Regression Model(QRM).QRM was the most accurate one,still the differences were not high even considering the simpler LRM model.
基金supported by the Italian National Institute of Nuclear Physics(INFN)partially funded by the Italian Ministry of Research in the framework of FIRB–Fondo per gli Investimenti della Ricerca di Base(No.RBFR12NK5K)
文摘This paper reports the fabrication of Nb thin films through pulsed laser deposition at different substrate temperatures, ranging from 300 to 660 K. While the variation of the substrate temperature does not affect significantly the excellent Nb thin film adhesion to the Si（100） substrate surface, the increase of the substrate temperature up to 570 K promotes an improvement of the grown film in terms of morphology and roughness. Such improvement is achieved through the formation of wider columnar structures with a reduced superficial roughness, around 5 nm, as shown by scanning electron microscopy（SEM） and atomic force microscopy. The use of temperatures over 570 K increases the substrate roughness due to the formation of irregular structures inside the film, as observed by SEM cross section analysis, and does not produce a relevant improvement on the crystalline structure of the material.
基金support by the European Union’s Horizon 2020 research and innovation program through the project BioCombs4Nanofibres(Grant Agreement No.862016)。
文摘We present a novel approach for tailoring the laser induced surface topography upon femtosecond(fs)pulsed laser irradiation.The method employs spatially controlled double fs laser pulses to actively regulate the hydrodynamic microfluidic motion of the melted layer that gives rise to the structures formation.The pulse train used,in particular,consists of a previously unexplored spatiotemporal intensity combination including one pulse with Gaussian and another with periodically modulated intensity distribution created by Direct Laser Interference Patterning(DLIP).The interpulse delay is appropriately chosen to reveal the contribution of the microfluidic melt flow,while it is found that the sequence of the Gaussian and DLIP pulses remarkably influences the surface profile attained.Results also demonstrate that both the spatial intensity of the double pulse and the effective number of pulses per irradiation spot can further be modulated to control the formation of complex surface morphologies.The underlying physical processes behind the complex patterns’generation were interpreted in terms of a multiscale model combining electron excitation with melt hydrodynamics.We believe that this work can constitute a significant step forward towards producing laser induced surface structures on demand by tailoring the melt microfluidic phenomena.
文摘Despite that organic-inorganic lead halide perovskites have attracted enormous scientific attention for energy conversion applications over the recent years,the influence of temperature and the type of the employed hole transport layer(HTL)on the charge carrier dynamics and recombination processes in perovskite photovoltaic devices is still largely unexplored.In particular,significant knowledge is missing on how these crucial parameters for radiative and non-radiative recombinations,as well as for efficient charge extraction vary among different perovskite crystalline phases that are induced by temperature variation.Herein,we perform micro photoluminescence(pPL)and ultrafast time resolved transient absorption spectroscopy(TAS)in Glass/Perovskite and two dierent Glass/ITO/HTL/Perovskite configurations at temperatures below room temperature,in order to probe the charge carrier dynamics of different perovskite crystalline phases,while considering also the effect of the employed HTL polymer.Namely,CH_(3)NH_(3)Pbb films were deposited on Glass,PEDOT:PSS and PTAA polymers,and the developed Glass/CH_(3)NH_(3)PbI_(3)and Glass/ITO/HTL/CH_(3)NH_(3)PbI_(3)architectures were studied from 85 K up to 215 K in order to explore the charge extraction dynamics of the CH_(3)NH_(3)PbI_(3)orthorhombic and tetragonal crystalline phases.It is observed an unusual blueshift of the bandgap with temperature and the dual emission at temperature below of 100 K and also,that the charge carrier dynamics,as expressed by hole injection times and free carrier recombination rates,are strongly depended on the actual pervoskite crystal phase,as well as,from the selected hole transport material.
基金Projects(862016(Bio Combs4Nanofibres)HELLAS-CH+1 种基金MIS 5002735) funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” and co-financed by Greece and the EU (European Regional Development Fund)Project (COST Action TUMIEE) supported by COST-European Cooperation in Science and Technology。
文摘Femtosecond pulsed lasers have been widely used over the past decades due to their capability to fabricate precise patterns at the micro-and nano-lengths scales. A key issue for efficient material processing is the determination of the laser parameters used in the experimental set ups. Despite a systematic investigation that has been performed to highlight the impact of every parameter independently, little attention has been drawn on the role of the substrate material on which the irradiated solid is placed. In this work, the influence of the substrate is emphasised for films of various thicknesses, which demonstrates that both the optical and thermophysical properties of the substrate affect the thermal fingerprint on the irradiated film while the impact is manifested to be higher at smaller film sizes. Two representative materials, silicon and fused silica, have been selected as typical substrates for thin films(gold and nickel) of different optical and thermophysical behaviour and the thermal response and damage thresholds are evaluated for the irradiated solids. The pronounced influence of the substrate is aimed to pave the way for new and more optimised designs of laserbased fabrication set ups and processing schemes.
基金supported by the National Key R&D Program of China(2017YFA0303403)the National Natural Science Foundation of China under Grants No.11374063 and 11404348+1 种基金the National Basic Research Program of China(973 Program)under Grant No.2013CBA01505.supported by the U.S.Department of Energy,Office of Basic Energy Science,Division of Materials Science and Engineering(Ames Laboratory is operated for the U.S.Department of Energy by Iowa State University under Contract No.DE-AC02-07CH11358)The European Research Council under ERC Advanced Grant No.320081(PHOTOMETA)supports the work at FORTH.
文摘By using a first-principles approach,monolayer PbI_(2)is found to have great potential in thermoelectric applications.The linear Boltzmann transport equation is applied to obtain the perturbation to the electron distribution by different scattering mechanisms.The mobility is mainly limited by the deformation-potential interaction with long-wavelength acoustic vibrations at low carrier concentrations.At high concentrations,ionized impurity scattering becomes stronger.The electrical conductivity and Seebeck coefficient are calculated accurately over various ranges of temperature and carrier concentration.The lattice thermal conductivity of PbI_(2),0.065 W m^(−1)K^(−1)at 300 K,is the lowest among other 2D thermoelectric materials.Such ultralow thermal conductivity is attributed to large atomic mass,weak interatomic bonding,strong anharmonicity,and localized vibrations in which the vast majority of heat is trapped.These electrical and phonon transport properties enable a high thermoelectric figure of merit over 1 for both p-type and n-type doping from 300 K to 900 K.A maximum zT of 4.9 is achieved at 900 K with an electron concentration of 1.9×10^(12)cm^(−2).Our work shows exceptionally good thermoelectric energy conversion efficiency in monolayer PbI_(2),which can be integrated to the existing photovoltaic devices.
文摘Metal halide perovskites stand at the nexus of materials innovation,nanoscale engineering,and real-world device integration.Their journey from laboratory curiosities to contenders for commercial photovoltaics,radiation detectors,and photocatalytic systems has been propelled not only by exceptional optoelectronic properties—but decisively,by how they are fabricated,structured,and interfaced.This Special Issue of Light:Advanced Manufacturing,titled“Perovskite Nanomaterials and Nanostructures Fabrication for Photonics and Optoelectronics”,showcases a new generation of research where synthesis,nanostructuring,and interfacial control converge to solve long-standing challenges:instability in operational environments,poor reproducibility,scalability bottlenecks,and performance ceilings.
基金supported by grants from the National Natural Science Foundation of China(52225606,52172248)Shenzhen Science and Technology Program(2023A010).
文摘Photocatalytic water splitting technology can directly convert solar energy into H_(2) via a zero-carbon route,offering a sustainable solution for solar utilization and H_(2) supply.Among various developed photocatalysts,Z-scheme heterojunction mimicking natural photosynthesis by combining two dissimilar semiconductors for redox reactions in series has unequivocally demonstrated its superiority in enhanced charge transfer,robust redox driving force,and wide optical absorption range.A comprehensive understanding on the fundamental principles of interface engineering between semiconductor components is the key to construct an efficient Z-scheme heterojunction.By focusing on different types of semiconductors,this article thoroughly expounds the coupling principles of components in binary mediator-free and ternary solid-mediator Z-scheme heterojunctions for photocatalytic water splitting,from the viewpoint of band structure alignment and interfacial electric field design.In addition to the well summarized research progresses in recent years,perspectives on the challenges and opportunities for developing advanced Z-scheme heterojunctions are provided.
基金a research grant from the Hellenic Ministry of Education with the acronym FORECO(11SYN-8-944)under the program SYNERGASIA 11 within ESPA 2007e2013The support of project“Electronics Beyond Silicon Era”(ELBESIER)ErasmustΚА2 programme acknowledged.Also,this work was carried out as part of European funding programs under the FP7 Clear-up IP project no 211948 and FP7 REGPOT 20122013 under grant agreement No 316165.
文摘The photocatalytic oxidation of gaseous benzene,toluene and xylene(BTX)over un-doped,0.1 and 1 wt%Mn-TiO_(2)nanoparticles under ultraviolet and visible irradiation was studied in atmosphere of synthetic air or inert gas.The photocatalytic decomposition efficiency and the oxidation products were determined using a Static Photochemical Reactor coupled with FTIR spectroscopy.BTX underwent efficient decomposition over Mn-TiO_(2)photocatalysts under UV irradiation,more with oxygen presence and less without oxygen.More important toluene and xylene went substantial decomposition over 0.1 mol%Mn-TiO_(2)under visible irradiation with oxygen presence.The main final oxidation products in the UV photocatalysis of BTX were CO_(2),CO and H2O,with CO_(2) and CO yields 4 and 2 respectively.The conversion percentage of benzene,toluene,and xylene to CO_(2) were 63.6%,56.4%,51.8%,and to CO 29%,26.5%,23.2%,respectively.In the visible photocatalysis of toluene and xylene the yields of CO were insignificant.Formation of carbon containing deposits on TiO_(2)surfaces was observed after extensive UV photocatalysis of toluene and xylene,and such by-products surface coverage may reduce the photocatalytic activity of TiO_(2)samples.Some aspects of the photocatalytic mechanism were examined.
基金financially supported by the National Natural Science Foundation of China (52225606 and 52172248)Shenzhen Science and Technology Program (2023A010)+1 种基金the"Fundamental Research Funds for the Central Universities""The Youth Innovation Team of Shaanxi Universities"。
基金supported by the National Priorities Research Program grant No.NPRP11S-1128-170042 from the Qatar National Research Fund(member of The Qatar Foundation)the H2020 Laserlab-Europe(EC-GA 871124)+2 种基金the H2020 MIRBOSE(EC-GA 737017)the“HELLAS-CH”(MIS 5002735)co-financed by Greece and the European Union.
文摘Strong terahertz(THz)electric and magnetic transients open up new horizons in science and applications.We review the most promising way of achieving sub-cycle THz pulses with extreme field strengths.During the nonlinear propagation of two-color mid-infrared and far-infrared ultrashort laser pulses,long,and thick plasma strings are produced,where strong photocurrents result in intense THz transients.The corresponding THz electric and magnetic field strengths can potentially reach the gigavolt per centimeter and kilotesla levels,respectively.The intensities of these THz fields enable extreme nonlinear optics and relativistic physics.We offer a comprehensive review,starting from the microscopic physical processes of light-matter interactions with mid-infrared and far-infrared ultrashort laser pulses,the theoretical and numerical advances in the nonlinear propagation of these laser fields,and the most important experimental demonstrations to date.
文摘We herein present a simple,fast,low-temperature,post-glass melting fabrication protocol in which a photochromic silver cation based modified zone is incorporated within silver metaphosphate glass(AgPO_(3)).The selection of AgPO_(3)glass is mainly based on its relative“soft”nature(T_(g)=192℃)that enables the integration of silver cations from the surface deposited AgCl layer,while being transparent in most of the visible range,and therefore suitable for smart photochromic window applications.The suggested synthesis procedure permits the controlled formation of a silver cation modified layer within the host glass matrix,while the characteristics of the layer itself can be adjusted correspondingly.Our findings reveal a direct relationship between the developed composite AgCleAgPO_(3)glass photochromic response and the morphological features of the integrated layer,i.e.,thickness and position.More importantly,the photochromic response time with various UV irradiation doses is also studied,where remarkable response times of several seconds are obtained.Processes and efforts to further enhance the photochromic performance by utilizing the presence of silver nanoparticles within the glass matrix are also presented and discussed.
基金This work was supported by the FLAG-ERA grant PeroGaS by General Secretariat for Research and Innovation(GSRI)(MIS 5070514)K.B.acknowledges E.U.H2020 Research and Innovation Program under Grant Agreement N820677Greek State Schol-arships Foundation(IKY)through the operational Program«Human Resources Development,Education and Lifelong Learning»in the context of the project“Reinforcement of Postdoctoral Researchers-2nd Cycle”(MIS-5033021).
文摘Highly-sensitive and stable ozone and hydrogen sensing elements were fabricated based on well-crystalline rounded cube-shaped CsPbBr 3 microcrystals,synthesized by a facile solution process per-formed under ambient conditions.It is shown that such elements demonstrate enhanced room tem-perature gas sensing ability compared to the previously reported metal halide and oxide-based ones.Electrical measurements performed on these sensing components revealed high sensitivity to ultra-low ozone and hydrogen concentrations,namely 4 ppb and 1 ppm respectively,as well as a remarkable repeatability,even after a few months of storage in ambient conditions.Both ozone and hydrogen sensors were self-activated,as they did not require the use of UV or heating external stimuli to operate,and exhibited fast detection and short restoration times.All such attractive properties along with the simple fabrication process could provide an easy,efficient and low-cost technology for the realization of future gas sensing devices.
基金supported by the Royal Society,ERC Starting(Grant No.639217)he European Union Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Global Fellowship(Grant No.703916)+10 种基金the National Natural Science Foundation of China(Grant Nos.11233001,11773014,11633007,11403074,11333005,11503008,and 11590781)the National Basic Research Program of China(Grant No.2015CB857100)NASA(Grant No.NNX13AD28A)an ARC Future Fellowship(Grant No.FT120100363)the National Science Foundation(Grant No.PHY-1430152)the Spanish MINECO(Grant No.AYA2016-76012-C3-1-P)the ICCUB(Unidad de Excelencia’Maria de Maeztu’)(Grant No.MDM-2014-0369)EU’s Horizon Programme through a Marie Sklodowska-Curie Fellowship(Grant No.702638)the Polish National Science Center(Grant Nos.2015/17/B/ST9/03422,2015/18/M/ST9/00541,2013/10/M/ST9/00729,and 2015/18/A/ST9/00746)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA15020100)the NWO Veni Fellowship(Grant No.639.041.647)
文摘In this White Paper we present the potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies related to Observatory Science targets. These include flaring stars, supernova remnants, accreting white dwarfs, low and high mass X-ray binaries, radio quiet and radio loud active galactic nuclei, tidal disruption events, and gamma-ray bursts. eXTP will be excellently suited to study one common aspect of these objects: their often transient nature. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Science, the eXTP mission is expected to be launched in the mid 2020s.
基金Innovation and Technology Commission of Hong Kong SAR,Grant/Award Number:ITS/027/22MXPriority 2030 Federal Academic Leadership Program+1 种基金National Natural Science Foundation of China,Grant/Award Number:62350610272Department of Science and Technology of Shandong Province,Grant/Award Numbers:2024HWYQ-082,79018006/006,KY0020240040。
文摘Hydrogen halide gases are one of the most wide‐spread pollutants of atmosphere,which are generated by various industrial sectors or natural processes,and may dramatically affect human health above certain thresholds of exposure.Hence,it is critically important to develop effective sensing methods for these gases.Herein,we review the recent progress as well as fundamental mechanisms,materials,and designs for the hydrogen halide gas sensors.We discuss in detail four major types of sensors:acoustic,chemical,optical,and the emerging nanophotonic sensors,categorizing them based on their operation principles.Acoustic sensors are discussed with a focus on microbalance‐based and surface acoustic wave gas sensors.Chemical sensors are considered from the point of view of electrochemical and chemiresistive sensing mechanisms.Optical sensors are analyzed,covering fluorescence‐based optical sensors,laser absorption‐based techniques,photoacoustic spectroscopy,and nonlinear optical methods.Finally,emerging nanophotonic sensors are introduced,emphasizing plasmonic and all‐dielectric nanophotonic approaches.We offer insights into the key operation mech-anisms of different types of sensors for hydrogen halide gases and provide their direct comparison.
