Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract in...Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract intensive studies of their advantages due to low-level ion migration and decent stability.However,there is still a lack of methods to precisely construct heterostructures and a fundamental understanding of their structure-dependent optoelectronic properties.Herein,a gas-phase method was developed to grow 2D perovskites directly on 3D perovskites with nanoscale accuracy.In addition,the larger steric hindrance of organic layers of 2D perovskites was proved to enable slower ion migration,which resulted in reduced trap states and better stability.Based on MAPbBr_(3)single crystals with the(PA)_(2)PbBr_(4)capping layer,the X-ray detector achieved a sensitivity of 22,245μC Gy_(air)^(−1)cm^(−2),a response speed of 240μs,and a dark current drift of 1.17.10^(–4)nA cm^(−1)s^(−1)V^(−1),which were among the highest reported for state-of-the-art perovskite-based X-ray detectors.This study presents a precise synthesis method to construct perovskite-based heterostructures.It also brings an in-depth understanding of the relationship between lattice structures and properties,which are beneficial for advancing high-performance and cost-effective X-ray detectors.展开更多
In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with ...In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, energy dispersive X-ray（EDS）, X-ray diffraction（XRD）, UV–vis diffuse reflectance spectroscopy（DRS） and vibrating sample magnetometer（VSM） techniques. The photocatalytic activity of FeO@SiO@TiO@Ho was investigated by degradation of methyl orange（MO） as cationic dye and rhodamine B（Rh B） as anionic dye in aqueous solution under UV/vis irradiation. The results indicate that about 92.1% of Rh B and78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results show that FeO@SiO@TiO@Ho nanoparticles are better photocatalyst than Fe3O4@Si O2@TiO 2@Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles.展开更多
Lanthanide ions doped luminescent materials are widely studied for latent fingerprint detection.However,most of these materials are synthesized at very high temperatures and use UV C light for visualization,which is h...Lanthanide ions doped luminescent materials are widely studied for latent fingerprint detection.However,most of these materials are synthesized at very high temperatures and use UV C light for visualization,which is harmful to eye,skin,etc.Herein,the Gd_(0.95)Eu_(0.05)PO_(4) nanorods synthesized by a simple co-precipitation method at 185℃ were reported for latent fingerprint visualization under 395 nm light.The Gd_(0.95)Eu_(0.05)PO_(4) nanomaterial has monoclinic crystal structure and shows rod-shaped morphology.Further,these Gd_(0.95)Eu_(0.05)PO_(4) nanorods exhibit excellent photoluminescence properties and strong fuchsia emission under UV light.These nanorods have been employed for developing latent fingerprints on various porous and non-porous substrates by the powder dusting technique,which exhibits clear and well defined details with high contrast,selectivity and sensitivity under 395 nm UV light.Latent fingerprints developed after 72 h of their deposition also show clear contrast with these nanorods.Therefore,the Gd_(0.95)Eu_(0.05)PO_(4) nanorods can be used for latent fingerprint visualization applications.展开更多
The present study focuses on the thermal response of carbon fiber-reinforced phenolic composites, where the matrix has been modified with different reinforcements. Two types of materials, multiwalled carbon nanotubes ...The present study focuses on the thermal response of carbon fiber-reinforced phenolic composites, where the matrix has been modified with different reinforcements. Two types of materials, multiwalled carbon nanotubes and zirconium diboride （ZrB2）, were used in a new design of mixture to produce the heat- resistant ablative composite system. The CNT/ZrB2/carbon/phenolic nanocomposite （Z/NT-CR） system corresponding to CNT/carbon/phenolic nanocomposite （NT-CR） showed a reasonable decrease in mass loss and the ablation rate as compared to carbon/phenolic composite （CR）. However, substantial drop in two factors was found for Z/NT-CR as compared to carbon/phenolic and NT-CR. Ablation mechanisms for all three composites were investigated by thermal gravimetric analysis in conjunction with micro- structural studies using a field emission scanning electron microscope. The microstructural studies revealed that CNTs acted as an ablation resistant phase for protection against 2000 ℃, and the conversion from ZrB2 to ZrO2 played an important role as an insulator in the performance of char layer in the ablation resistance.展开更多
NdZrO–ZrOnanocomposites were prepared via a facile process with propylene glycol as novel connecting agent and benzene tricarboxylic acid as a new complexing agent. The as-obtained NdZrO–ZrOnanocomposites were chara...NdZrO–ZrOnanocomposites were prepared via a facile process with propylene glycol as novel connecting agent and benzene tricarboxylic acid as a new complexing agent. The as-obtained NdZrO–ZrOnanocomposites were characterized by transmission electron microscopy（TEM）, UV–vis diffuse reflectance spectroscopy, energy dispersive X-ray microanalysis（EDX）, Fourier transform infrared（FT-IR）spectroscopy, field emission scanning electron microscopy（FESEM）, and X-ray diffraction（XRD）. According to the morphological studies of the as-synthesized nanocomposites, it was found that the shape and particle size of NdZrO–ZrOnanocomposites depended on the space-filling template type, dosage of space-filling template and tricarboxylic acid as complexing agent. NdZrO–ZrOnanocomposites with different shapes and grain sizes have been synthesized. The photocatalytic behavior of as-produced NdZrO–ZrOnanocomposites was also investigated through photodegradation of methylene blue dye and 2-naphthol as water pollutants.展开更多
The mechanism of single-walled carbon nanotubes （SWCNTs） aligning in the direction of external electric field is studied by quantum mechanics calculations. The rotational torque on the carbon nanotubes is proportion...The mechanism of single-walled carbon nanotubes （SWCNTs） aligning in the direction of external electric field is studied by quantum mechanics calculations. The rotational torque on the carbon nanotubes is proportional to the difference between the longitudinal and transverse polarizabilities and varies with the angle of SWCNTs to the external electric field. The longitudinal polarizability increases with second power of length, while the transverse polarizability increases linearly with length. A zigzag SWCNT has larger longitudinal and transverse polarizabilities than an armchair SWCNT with the same diameter and the discrepancy becomes larger for longer tubes.展开更多
The nanostructures of zinc chromite（Zn Cr2O4） were fabricated by the microwave method. It was shown that the well-crystallized spinel structure is formed after annealing at 700 °C. The influence of reaction tim...The nanostructures of zinc chromite（Zn Cr2O4） were fabricated by the microwave method. It was shown that the well-crystallized spinel structure is formed after annealing at 700 °C. The influence of reaction time and irradiation power of oven on the size and shape of the as-prepared Zn Cr2O4 samples was studied. The synthesized samples were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, energy dispersive X-ray（EDX）, transmission electron microscopy（TEM）, diffuse reflectance spectroscopy（DRS）, photoluminescence（PL） spectroscopy, Fourier transform infrared（FTIR） spectra and vibrating sample magnetometry（VSM）, respectively. The optical band gap calculated using DRS was found to be 3.50 e V for Zn Cr2O4 nanostructures. Photoluminescence measurements also confirmed this result.展开更多
Barium molybdate（Ba Mo O4） micro- and nano-crystals were synthesized by the coprecipitation method. Utilizing the water as the solvent provides octahedron-like nanostructures. These nano-crystals were structurally c...Barium molybdate（Ba Mo O4） micro- and nano-crystals were synthesized by the coprecipitation method. Utilizing the water as the solvent provides octahedron-like nanostructures. These nano-crystals were structurally characterized by X-ray diffraction, energy dispersive X-ray micro-analysis, Fourier transform infrared spectra. The size and shape were observed by scanning electron microscopy. The optical properties were studies by ultraviolet-visible diffuse reflectance spectroscopy and photoluminescence measurements at room temperature. The effects of temperature, solvent, surfactant and barium source were considered to obtain a controlled shape. It is found that the morphology, particle size and phase of the final products are extremely affected by these parameters.展开更多
We report on a first-principles study of a novel band modulation in zigzag double-walled boron nitride nan- otubes （DBNNTs） by applying radial strain and coupled ex- ternal electric field. We show that the band alig...We report on a first-principles study of a novel band modulation in zigzag double-walled boron nitride nan- otubes （DBNNTs） by applying radial strain and coupled ex- ternal electric field. We show that the band alignment be- tween the inner and outer walls of the DBNNTs can be tuned from type I to type II with increasing radial strain, accompa- nied with a direct to indirect band gap transition and a sub- stantial gap reduction. The band gap can be further signifi- cantly reduced by applying a transverse electric field. The coupling of electric field with the radial strain makes the field-induced gap reduction being anisotropic and more re- markable than that in undeformed DBNNTs. In particular, the gap variation induced by electric field perpendicular to the radial strain is the most remarkable among all the modu-lations. These tunable properties by electromechanical cou- pling in DBNNTs will greatly enrich their versatile applica- tions in future nanoelectronics.展开更多
Mercury sulfide (HgS) crystals with different morphologies and particle sizes, were obtained via a simple microwave reaction by a new precursor complex, [bis ((2-suphanylphenyl)imino]methylphenol) Hg(II)] ([Hg(C13H11N...Mercury sulfide (HgS) crystals with different morphologies and particle sizes, were obtained via a simple microwave reaction by a new precursor complex, [bis ((2-suphanylphenyl)imino]methylphenol) Hg(II)] ([Hg(C13H11NSO)2]2+). The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV?Vis) spectroscopy. Mercury sulfide nanostructures with different sizes were prepared. The effects of precursor concentration, type of solvent, microwave time, and power on the particle size and morphology were investigated. The results show that the type of solvent and microwave power play key roles in the final size of HgS. Ethylene glycol is the best solvent for the synthesis of very fine particles of HgS, and the best power for the preparation of HgS nanoparticles with uniform size distribution is 900 W. The band gap for HgS nanoparticles calculated by UV–Vis spectrum was 3.2 eV which had about 1.2 eV blue shift in comparison with the band gap of 2 eV for bulk sample.展开更多
Indium nanorods are grown on silicon substrates by using magnetron-sputtering technique. Film morphologies and nanorod microstructure are investigated by using scanning electron microscopy, high-resolution transmissio...Indium nanorods are grown on silicon substrates by using magnetron-sputtering technique. Film morphologies and nanorod microstructure are investigated by using scanning electron microscopy, high-resolution transmission electron microscopy （HRTEM）, and x-ray diffraction. It is found that the mean diameter of the nanorods ranges from 30nm to 100nm and the height ranges from 30nm to 200nm. The HRTEM investigations show that the indium nanorods are single crystals and grow along the [100] axis. The nanorods grow from the facets near the surface undulation that is caused by compressive stress in the indium grains generated during grain coalescence process. For low melting point and high diffusivity metal, such as bismuth and indium, this spontaneous nanorod growth mechanism can be used to fabricate nanostructures.展开更多
Seawater is the most abundant source of molecular hydrogen.Utilizing the hydrogen reserves present in the seawater may inaugurate innovative strategies aimed at advancing sustainable energy and environmental preservat...Seawater is the most abundant source of molecular hydrogen.Utilizing the hydrogen reserves present in the seawater may inaugurate innovative strategies aimed at advancing sustainable energy and environmental preservation endeavors in the future.Recently,there has been a surge in study in the field addressing the production of hydrogen through the electrochemical seawater splitting.However,the performance and durability of the electrode have limitations due to the fact that there are a few challenges that need to be addressed in order to make the technology suitable for the industrial purpose.The active site blockage caused by chloride ions that are prevalent in seawater and chloride corrosion is the most significant issue;it has a negative impact on both the activity and the durability of the anode component.Addressing this particular issue is of upmost importance in the seawater splitting area.This review concentrates on the newly developed materials and techniques for inhibiting chloride ions by blocking the active sites,simultaneously preventing the chloride corrosion.It is anticipated that the concept will be advantageous for a large audience and will inspire researchers to study on this particular area of concern.展开更多
Metal-supported solid oxide fuel cells(MS-SOFCs)have recently gained significant attention as an advanced SOFC technology,owing to their excellent mechanical robustness,ease of handling,and high manufacturability.The ...Metal-supported solid oxide fuel cells(MS-SOFCs)have recently gained significant attention as an advanced SOFC technology,owing to their excellent mechanical robustness,ease of handling,and high manufacturability.The use of metal substrates enables improved durability under thermal and redox cycling,and allows for thinner electrolyte layers,contributing to enhanced performance.However,their fabrication typically requires high-temperature sintering to ensure adequate material properties and adhesion,as most SOFC components are ceramic.These high-temperature processes can lead to undesirable effects,including metal support oxidation,chemical side reactions,and accelerated particle growth,which degrade cell performance.This study introduces an ultra-fast sintering approach for MS-SOFC fabrication by directly integrating stainless-steel metal supports with nickel-yttria-stabilized zirconia(Ni-YSZ)composite anode active layers.The application of flash light sintering-an innovative ultra-fast technique-effectively suppressed Ni catalyst particle growth,expanding the electrochemical reaction area while minimizing material diffusion between the metal support and anode layer.As a result,the fabricated cells achieved a stable open-circuit voltage(OCV)exceeding 1 V at 650℃ and a peak power density of 412 mW/cm^(2),representing an approximately 426.3% performance improvement over conventionally sintered cells.This research presents a transformative strategy for SOFC manufacturing,addressing the challenges of conventional long-duration heat treatments and demonstrating significant potential for advancing energy conversion technologies.展开更多
Using the hydrothermal method, lanthanum hydroxide nanorods were synthesized by the reaction of LaC13·7H20, ethyl- enediamine, and hydrazine. According to SEM results, ethylenediamine and hydrazine with pH manage...Using the hydrothermal method, lanthanum hydroxide nanorods were synthesized by the reaction of LaC13·7H20, ethyl- enediamine, and hydrazine. According to SEM results, ethylenediamine and hydrazine with pH management could control the parti- cle growth and played an important role in formation of lanthanum hydroxide nanorods. The morphology and microstructure of the obtained products were characterized by X-ray diffraction （XRD） spectra, energy-dispersive X-ray spectroscopy （EDX）, Fourier transformed infi＇ared （FTIR） spectrum, transmission electron microscopy （TEM）, and scanning electron microscopy （SEM）. Further- more, the effects of the molar ratio of the precursors as well as the reaction temperature and time on the morphology and particle size of the products were investigated.展开更多
12-Tungstophosphoric acid（PW） supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization（ODS） of mixed thiophenic compounds in model oil and crude oil under mild conditions u...12-Tungstophosphoric acid（PW） supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization（ODS） of mixed thiophenic compounds in model oil and crude oil under mild conditions using hydrogen peroxide（H2O2） as an oxidizing agent. A one-factor-at-a-time method was applied for optimizing the parameters such as temperature, reaction time, amount of catalyst, type of extractant and oxidant-tosulfur compounds（S-compounds） molar ratio. The corresponding products can be easily removed from the model oil by using ethanol as the best extractant. The results showed high catalytic activity of PW/KSF in the oxidative removal of dibenzothiophene（DBT） and mixed thiophenic model oil under atmospheric pressure at 75 ℃ in a biphasic system. To investigate the oxidation and adsorption effects of crude oil composition on ODS, the effects of cyclohexene, 1,7-octadiene and o-xylene with different concentrations were studied.展开更多
A facile approach was developed to prepare Dy2Ce2O7 nanostructures. Dy2Ce2O7 nanostructures were prepared by applying cerium（IV） ammonium nitrate and dysprosium nitrate as Ce and Dy precursors. It was found that the...A facile approach was developed to prepare Dy2Ce2O7 nanostructures. Dy2Ce2O7 nanostructures were prepared by applying cerium（IV） ammonium nitrate and dysprosium nitrate as Ce and Dy precursors. It was found that the kind of connecting agent, space-filling template and chelating agent were significant factors for the control in shape and size. Transmission electron microscopy（TEM）, X-ray diffraction（XRD）, diffuse reflectance UV-vis spectroscopy（DR-UV-vis）, field emission scanning electron microscopy（FESEM）, photoluminescence spectroscopy（PL） and energy dispersive X-ray microanalysis（EDX） techniques were applied to characterize the Dy2Ce2O7 nanostructures and investigate their optical characteristics. To examine the photocatalytic activity of as-produced Dy2Ce2O7 nanostructures, the photocatalytic degradation of erythrosine dye as water pollutant was carried out. The results of the photocatalytic investigations suggest as-obtained nano-sized Dy2Ce2O7 product as a new, proper and efficient candidate for photocatalytic usages under UV illumination.展开更多
Mn-Zn ferrites doped with different contents of Sm^（3＋） and Gd^（3＋） ions were prepared by sol-gel auto-combustion method and characterized by Fourier transform infrared spectroscopy（FTIR）, thermogravimetric an...Mn-Zn ferrites doped with different contents of Sm^（3＋） and Gd^（3＋） ions were prepared by sol-gel auto-combustion method and characterized by Fourier transform infrared spectroscopy（FTIR）, thermogravimetric analysis（TG）, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and vibrating sample magnetometer（VSM）. When samples were calcined in a relatively low temperature below 1100 °C, secondary phases（α-Fe_2O_3） could be identified. Therefore, in order to acquire pure and better crystallinity, the suitable calcining temperature of powders was selected at 1200 °C. It was also found that all the samples consisting of ferrite phases of typical spinel cubic structure and average crystallite sizes between 31.5 and 38.2 nm were obtained after calcining at 1200 oC for 4 h. The lattice parameters increased almost linearly with increasing Sm content. A dense microstructure was obtained after sintering at 1250 °C for 4 h. Through the analysis of magnetic properties, hysteresis loops for all the samples were narrow with low values of coercivity and retentivity, indicating the paramagnetic nature of these samples. And saturation magnetization Ms strongly depended on the type of additive to reach a maximum of 47.99 emu/g for x=0.015, which showed a great promise for hyperthermia applications.展开更多
Herein,we examine the performance of dye-sensitized solar cells containing five D-π-A organic dyes designed by systematic modification of π-bridge size and geometric structure.Each dye has a simple push-pull structu...Herein,we examine the performance of dye-sensitized solar cells containing five D-π-A organic dyes designed by systematic modification of π-bridge size and geometric structure.Each dye has a simple push-pull structure with a triarylamino group as an electron donor,bithiophene-4,4-dimethyl-4 H-cyclopenta 1,2-b:5,4-b’]dithiophene(M11),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophenethiophene(M12),thiophene-4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M13),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene-benzene(M14),and 4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M15)units asπ-bridges,and cyanoacrylic acid as an electron acceptor/anchor.The extension of theπ-bridge linkage favors wide-range absorption but,because of the concomitant molecular volume increase,hinders the efficient adsorption of dyes on the TiO_(2) film surface.Hence,higher loadings are achieved for smaller dye molecules,resulting in(i)a shift of the TiO_(2) conduction band edge to more negative values,(ii)a greater photocurrent,and(iii)suppressed charge recombination between the photoanode and the redox couple in the electrolyte.Consequently,under one-sun equivalent illumination(AM 1.5 G,100 mW/cm^(2)),the highest photovoltage,photocurrent,and conversion efficiency(η=7.19%)are observed for M15,which has the smallest molecular volume among M series dyes.展开更多
Hydrogen spillover effect has recently garnered a lot of attention in the field of electrocatalytic hydrogen evolution reactions.A new avenue for understanding the dynamic behavior of atomic migration in which hydroge...Hydrogen spillover effect has recently garnered a lot of attention in the field of electrocatalytic hydrogen evolution reactions.A new avenue for understanding the dynamic behavior of atomic migration in which hydrogen atoms moving on a catalyst surface was opened up by the setup of the word"hydrogen spillover."However,there is currently a dearth of thorough knowledge regarding the hydrogen spillover effect.Currently,the advancement of sophisticated characterization procedures offers progressively useful information to enhance our grasp of the hydrogen spillover effect.The understanding of material fabrication for hydrogen spillover effect has erupted.Considering these factors,we made an effort to review most of the articles published on the hydrogen spillover effect and carefully analyzed the aspect of material fabrication.All of our attention has been directed toward the molecular pathway that leads to improve hydrogen evolution reactions performance.In addition,we have attempted to elucidate the spillover paths through the utilization of DFT calculations.Furthermore,we provide some preliminary research suggestions and highlight the opportunities and obstacles that are still to be confronted in this study area.展开更多
Eco-friendly and antimicrobial globular protein lysozyme is widely produced for several commercial applications.Interestingly,it can also be able to convert mechanical and thermal energy into electricity due to its pi...Eco-friendly and antimicrobial globular protein lysozyme is widely produced for several commercial applications.Interestingly,it can also be able to convert mechanical and thermal energy into electricity due to its piezo-and pyroelectric nature.Here,we demonstrate engineering of lysozyme into piezoelectric devices that can exploit the potential of lysozyme as environmentally friendly,biocompatible material for mechanical energy harvesting and sensorics,especially in micropowered electronic applications.Noteworthy that this flexible,shape adaptive devices made of crystalline lysozyme obtained from hen egg white exhibited a longitudinal piezoelectric charge coefficient(d-2.7 pC N^(-1))and piezoelectric voltage coefficient(g-76.24 mVmN^(-1))which are comparable to those of quartz(-2.3 pC N^(-1) and 50 mVmN^(-1)).Simple finger tapping on bio-organic energy harvester(BEH)made of lysozyme produced up to 350 mV peak-to-peak voltage,and a maximum instantaneous power output of 2.2 nW cm^(-2).We also demonstrated that the BEH could be used for self-powered motion sensing for real-time monitoring of different body functions.These results pave the way toward self-powered,autonomous,environmental-friendly bio-organic devices for flexible energy harvesting,storage,and in wearable healthcare monitoring.展开更多
基金support from National Key Research and Development Program of China(2024YFE0217100)the National Natural Science Foundation of China(21905006,22261160370,and 62105075)+7 种基金the Guangdong Provincial Science and Technology Plan(2021A0505110003)the Natural Science Foundation of Hunan Province,China(2023JJ50132)Guangxi Department of Science and Technology(2020GXNSFBA159049 and AD19110030)the Shenzhen Science and Technology Program(SGDX20230116093205009,JCYJ20220818100211025 and 2022378670)the Natural Science Foundation of Top Talent of SZTU(GDRC202343)financial support of Innovation and Technology Fund(#GHP/245/22SZ)The University Grant Council of the University of Hong Kong(grant No.2302101786)General Research Fund(grant Nos.17200823 and 17310624)from the Research Grants Council.
文摘Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract intensive studies of their advantages due to low-level ion migration and decent stability.However,there is still a lack of methods to precisely construct heterostructures and a fundamental understanding of their structure-dependent optoelectronic properties.Herein,a gas-phase method was developed to grow 2D perovskites directly on 3D perovskites with nanoscale accuracy.In addition,the larger steric hindrance of organic layers of 2D perovskites was proved to enable slower ion migration,which resulted in reduced trap states and better stability.Based on MAPbBr_(3)single crystals with the(PA)_(2)PbBr_(4)capping layer,the X-ray detector achieved a sensitivity of 22,245μC Gy_(air)^(−1)cm^(−2),a response speed of 240μs,and a dark current drift of 1.17.10^(–4)nA cm^(−1)s^(−1)V^(−1),which were among the highest reported for state-of-the-art perovskite-based X-ray detectors.This study presents a precise synthesis method to construct perovskite-based heterostructures.It also brings an in-depth understanding of the relationship between lattice structures and properties,which are beneficial for advancing high-performance and cost-effective X-ray detectors.
基金the council of Iran National Science Foundation and University of Kashan for supporting this work by Grant No (159271/999)
文摘In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of FeO@SiO@TiO@Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, energy dispersive X-ray（EDS）, X-ray diffraction（XRD）, UV–vis diffuse reflectance spectroscopy（DRS） and vibrating sample magnetometer（VSM） techniques. The photocatalytic activity of FeO@SiO@TiO@Ho was investigated by degradation of methyl orange（MO） as cationic dye and rhodamine B（Rh B） as anionic dye in aqueous solution under UV/vis irradiation. The results indicate that about 92.1% of Rh B and78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results show that FeO@SiO@TiO@Ho nanoparticles are better photocatalyst than Fe3O4@Si O2@TiO 2@Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles.
基金Project supported by the Science and Engineering Research Board(SERB),India(ECR/2015/000333)。
文摘Lanthanide ions doped luminescent materials are widely studied for latent fingerprint detection.However,most of these materials are synthesized at very high temperatures and use UV C light for visualization,which is harmful to eye,skin,etc.Herein,the Gd_(0.95)Eu_(0.05)PO_(4) nanorods synthesized by a simple co-precipitation method at 185℃ were reported for latent fingerprint visualization under 395 nm light.The Gd_(0.95)Eu_(0.05)PO_(4) nanomaterial has monoclinic crystal structure and shows rod-shaped morphology.Further,these Gd_(0.95)Eu_(0.05)PO_(4) nanorods exhibit excellent photoluminescence properties and strong fuchsia emission under UV light.These nanorods have been employed for developing latent fingerprints on various porous and non-porous substrates by the powder dusting technique,which exhibits clear and well defined details with high contrast,selectivity and sensitivity under 395 nm UV light.Latent fingerprints developed after 72 h of their deposition also show clear contrast with these nanorods.Therefore,the Gd_(0.95)Eu_(0.05)PO_(4) nanorods can be used for latent fingerprint visualization applications.
文摘The present study focuses on the thermal response of carbon fiber-reinforced phenolic composites, where the matrix has been modified with different reinforcements. Two types of materials, multiwalled carbon nanotubes and zirconium diboride （ZrB2）, were used in a new design of mixture to produce the heat- resistant ablative composite system. The CNT/ZrB2/carbon/phenolic nanocomposite （Z/NT-CR） system corresponding to CNT/carbon/phenolic nanocomposite （NT-CR） showed a reasonable decrease in mass loss and the ablation rate as compared to carbon/phenolic composite （CR）. However, substantial drop in two factors was found for Z/NT-CR as compared to carbon/phenolic and NT-CR. Ablation mechanisms for all three composites were investigated by thermal gravimetric analysis in conjunction with micro- structural studies using a field emission scanning electron microscope. The microstructural studies revealed that CNTs acted as an ablation resistant phase for protection against 2000 ℃, and the conversion from ZrB2 to ZrO2 played an important role as an insulator in the performance of char layer in the ablation resistance.
基金the council of Iran National Science FoundationUniversity of Kashan for supporting this work by Grant No(159271/7579)
文摘NdZrO–ZrOnanocomposites were prepared via a facile process with propylene glycol as novel connecting agent and benzene tricarboxylic acid as a new complexing agent. The as-obtained NdZrO–ZrOnanocomposites were characterized by transmission electron microscopy（TEM）, UV–vis diffuse reflectance spectroscopy, energy dispersive X-ray microanalysis（EDX）, Fourier transform infrared（FT-IR）spectroscopy, field emission scanning electron microscopy（FESEM）, and X-ray diffraction（XRD）. According to the morphological studies of the as-synthesized nanocomposites, it was found that the shape and particle size of NdZrO–ZrOnanocomposites depended on the space-filling template type, dosage of space-filling template and tricarboxylic acid as complexing agent. NdZrO–ZrOnanocomposites with different shapes and grain sizes have been synthesized. The photocatalytic behavior of as-produced NdZrO–ZrOnanocomposites was also investigated through photodegradation of methylene blue dye and 2-naphthol as water pollutants.
基金Supported by the National Basic Research Programme of China under Grant No 2007CB936204, the Ministry of Education of China under Grant No 705021 and IRT0534, the National Natural Science Foundation of China under Grant No 10732040, and the Natural Science Foundation of Jiangsu Province.
文摘The mechanism of single-walled carbon nanotubes （SWCNTs） aligning in the direction of external electric field is studied by quantum mechanics calculations. The rotational torque on the carbon nanotubes is proportional to the difference between the longitudinal and transverse polarizabilities and varies with the angle of SWCNTs to the external electric field. The longitudinal polarizability increases with second power of length, while the transverse polarizability increases linearly with length. A zigzag SWCNT has larger longitudinal and transverse polarizabilities than an armchair SWCNT with the same diameter and the discrepancy becomes larger for longer tubes.
文摘The nanostructures of zinc chromite（Zn Cr2O4） were fabricated by the microwave method. It was shown that the well-crystallized spinel structure is formed after annealing at 700 °C. The influence of reaction time and irradiation power of oven on the size and shape of the as-prepared Zn Cr2O4 samples was studied. The synthesized samples were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, energy dispersive X-ray（EDX）, transmission electron microscopy（TEM）, diffuse reflectance spectroscopy（DRS）, photoluminescence（PL） spectroscopy, Fourier transform infrared（FTIR） spectra and vibrating sample magnetometry（VSM）, respectively. The optical band gap calculated using DRS was found to be 3.50 e V for Zn Cr2O4 nanostructures. Photoluminescence measurements also confirmed this result.
文摘Barium molybdate（Ba Mo O4） micro- and nano-crystals were synthesized by the coprecipitation method. Utilizing the water as the solvent provides octahedron-like nanostructures. These nano-crystals were structurally characterized by X-ray diffraction, energy dispersive X-ray micro-analysis, Fourier transform infrared spectra. The size and shape were observed by scanning electron microscopy. The optical properties were studies by ultraviolet-visible diffuse reflectance spectroscopy and photoluminescence measurements at room temperature. The effects of temperature, solvent, surfactant and barium source were considered to obtain a controlled shape. It is found that the morphology, particle size and phase of the final products are extremely affected by these parameters.
基金supported by the 973 Program(2012CB933403 and 2013CB932604)the National Natural Science Foundation of China(11172124 and 91023026)+5 种基金Jiangsu Province Natural Science Foundation(BK2011722)MOE doctoral discipline Foundation(20113218120033)China and Jiangsu Province Postdoctoral Science Foundation(2012T50494,20110490132 and 1002015B)the Fundamental Research Funds for the Central Universities(NS2012067)supported by the National Science Foundation(CMMI and NIRT)the U.S.Army Research Office MURI(W911NF-11-1-0362)
文摘We report on a first-principles study of a novel band modulation in zigzag double-walled boron nitride nan- otubes （DBNNTs） by applying radial strain and coupled ex- ternal electric field. We show that the band alignment be- tween the inner and outer walls of the DBNNTs can be tuned from type I to type II with increasing radial strain, accompa- nied with a direct to indirect band gap transition and a sub- stantial gap reduction. The band gap can be further signifi- cantly reduced by applying a transverse electric field. The coupling of electric field with the radial strain makes the field-induced gap reduction being anisotropic and more re- markable than that in undeformed DBNNTs. In particular, the gap variation induced by electric field perpendicular to the radial strain is the most remarkable among all the modu-lations. These tunable properties by electromechanical cou- pling in DBNNTs will greatly enrich their versatile applica- tions in future nanoelectronics.
基金council of University of Kashan for providing financial support to undertake this work by Grant No. 159271/368
文摘Mercury sulfide (HgS) crystals with different morphologies and particle sizes, were obtained via a simple microwave reaction by a new precursor complex, [bis ((2-suphanylphenyl)imino]methylphenol) Hg(II)] ([Hg(C13H11NSO)2]2+). The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV?Vis) spectroscopy. Mercury sulfide nanostructures with different sizes were prepared. The effects of precursor concentration, type of solvent, microwave time, and power on the particle size and morphology were investigated. The results show that the type of solvent and microwave power play key roles in the final size of HgS. Ethylene glycol is the best solvent for the synthesis of very fine particles of HgS, and the best power for the preparation of HgS nanoparticles with uniform size distribution is 900 W. The band gap for HgS nanoparticles calculated by UV–Vis spectrum was 3.2 eV which had about 1.2 eV blue shift in comparison with the band gap of 2 eV for bulk sample.
文摘Indium nanorods are grown on silicon substrates by using magnetron-sputtering technique. Film morphologies and nanorod microstructure are investigated by using scanning electron microscopy, high-resolution transmission electron microscopy （HRTEM）, and x-ray diffraction. It is found that the mean diameter of the nanorods ranges from 30nm to 100nm and the height ranges from 30nm to 200nm. The HRTEM investigations show that the indium nanorods are single crystals and grow along the [100] axis. The nanorods grow from the facets near the surface undulation that is caused by compressive stress in the indium grains generated during grain coalescence process. For low melting point and high diffusivity metal, such as bismuth and indium, this spontaneous nanorod growth mechanism can be used to fabricate nanostructures.
基金supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(RS-2024-00436563)supported by Brain Pool program funded by the Ministry of Science and ICT through the National Research Foundation of Korea(Grant No.RS-2023-00284361).
文摘Seawater is the most abundant source of molecular hydrogen.Utilizing the hydrogen reserves present in the seawater may inaugurate innovative strategies aimed at advancing sustainable energy and environmental preservation endeavors in the future.Recently,there has been a surge in study in the field addressing the production of hydrogen through the electrochemical seawater splitting.However,the performance and durability of the electrode have limitations due to the fact that there are a few challenges that need to be addressed in order to make the technology suitable for the industrial purpose.The active site blockage caused by chloride ions that are prevalent in seawater and chloride corrosion is the most significant issue;it has a negative impact on both the activity and the durability of the anode component.Addressing this particular issue is of upmost importance in the seawater splitting area.This review concentrates on the newly developed materials and techniques for inhibiting chloride ions by blocking the active sites,simultaneously preventing the chloride corrosion.It is anticipated that the concept will be advantageous for a large audience and will inspire researchers to study on this particular area of concern.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2024-00395914)the Korea Institute of Energy Technology Evaluation and Planning(KETEP)granted financial resource from the Ministry of Trade,Industry&Energy,Republic of Korea(20213030030040 and 20212020800090).
文摘Metal-supported solid oxide fuel cells(MS-SOFCs)have recently gained significant attention as an advanced SOFC technology,owing to their excellent mechanical robustness,ease of handling,and high manufacturability.The use of metal substrates enables improved durability under thermal and redox cycling,and allows for thinner electrolyte layers,contributing to enhanced performance.However,their fabrication typically requires high-temperature sintering to ensure adequate material properties and adhesion,as most SOFC components are ceramic.These high-temperature processes can lead to undesirable effects,including metal support oxidation,chemical side reactions,and accelerated particle growth,which degrade cell performance.This study introduces an ultra-fast sintering approach for MS-SOFC fabrication by directly integrating stainless-steel metal supports with nickel-yttria-stabilized zirconia(Ni-YSZ)composite anode active layers.The application of flash light sintering-an innovative ultra-fast technique-effectively suppressed Ni catalyst particle growth,expanding the electrochemical reaction area while minimizing material diffusion between the metal support and anode layer.As a result,the fabricated cells achieved a stable open-circuit voltage(OCV)exceeding 1 V at 650℃ and a peak power density of 412 mW/cm^(2),representing an approximately 426.3% performance improvement over conventionally sintered cells.This research presents a transformative strategy for SOFC manufacturing,addressing the challenges of conventional long-duration heat treatments and demonstrating significant potential for advancing energy conversion technologies.
基金the council of University of Kashan for their unending effort to provide financial support to undertake this work (159271/284)
文摘Using the hydrothermal method, lanthanum hydroxide nanorods were synthesized by the reaction of LaC13·7H20, ethyl- enediamine, and hydrazine. According to SEM results, ethylenediamine and hydrazine with pH management could control the parti- cle growth and played an important role in formation of lanthanum hydroxide nanorods. The morphology and microstructure of the obtained products were characterized by X-ray diffraction （XRD） spectra, energy-dispersive X-ray spectroscopy （EDX）, Fourier transformed infi＇ared （FTIR） spectrum, transmission electron microscopy （TEM）, and scanning electron microscopy （SEM）. Further- more, the effects of the molar ratio of the precursors as well as the reaction temperature and time on the morphology and particle size of the products were investigated.
基金Razi University Research Council for support of this work
文摘12-Tungstophosphoric acid（PW） supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization（ODS） of mixed thiophenic compounds in model oil and crude oil under mild conditions using hydrogen peroxide（H2O2） as an oxidizing agent. A one-factor-at-a-time method was applied for optimizing the parameters such as temperature, reaction time, amount of catalyst, type of extractant and oxidant-tosulfur compounds（S-compounds） molar ratio. The corresponding products can be easily removed from the model oil by using ethanol as the best extractant. The results showed high catalytic activity of PW/KSF in the oxidative removal of dibenzothiophene（DBT） and mixed thiophenic model oil under atmospheric pressure at 75 ℃ in a biphasic system. To investigate the oxidation and adsorption effects of crude oil composition on ODS, the effects of cyclohexene, 1,7-octadiene and o-xylene with different concentrations were studied.
基金supported by the Council of Iran National Science Foundation and University of Kashan(159271/9579)
文摘A facile approach was developed to prepare Dy2Ce2O7 nanostructures. Dy2Ce2O7 nanostructures were prepared by applying cerium（IV） ammonium nitrate and dysprosium nitrate as Ce and Dy precursors. It was found that the kind of connecting agent, space-filling template and chelating agent were significant factors for the control in shape and size. Transmission electron microscopy（TEM）, X-ray diffraction（XRD）, diffuse reflectance UV-vis spectroscopy（DR-UV-vis）, field emission scanning electron microscopy（FESEM）, photoluminescence spectroscopy（PL） and energy dispersive X-ray microanalysis（EDX） techniques were applied to characterize the Dy2Ce2O7 nanostructures and investigate their optical characteristics. To examine the photocatalytic activity of as-produced Dy2Ce2O7 nanostructures, the photocatalytic degradation of erythrosine dye as water pollutant was carried out. The results of the photocatalytic investigations suggest as-obtained nano-sized Dy2Ce2O7 product as a new, proper and efficient candidate for photocatalytic usages under UV illumination.
基金Project supported by the National Natural Science Foundation of China(51102073)the Natural Science Foundation of Education Department of Anhui Province of China(KJ2015A232,KJ2015B1105906)+3 种基金the Natural Science Foundation of Anhui Province of China(1308085QB35)the research fund of State Key Laboratory of Structural Chemistry(20110012)Anhui Province Outstanding Young Teachers Visit Abroad Training Projects(gxfxZD2016220)the Outstanding Young Talent Project in Colleges and Universities of Anhui Province
文摘Mn-Zn ferrites doped with different contents of Sm^（3＋） and Gd^（3＋） ions were prepared by sol-gel auto-combustion method and characterized by Fourier transform infrared spectroscopy（FTIR）, thermogravimetric analysis（TG）, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and vibrating sample magnetometer（VSM）. When samples were calcined in a relatively low temperature below 1100 °C, secondary phases（α-Fe_2O_3） could be identified. Therefore, in order to acquire pure and better crystallinity, the suitable calcining temperature of powders was selected at 1200 °C. It was also found that all the samples consisting of ferrite phases of typical spinel cubic structure and average crystallite sizes between 31.5 and 38.2 nm were obtained after calcining at 1200 oC for 4 h. The lattice parameters increased almost linearly with increasing Sm content. A dense microstructure was obtained after sintering at 1250 °C for 4 h. Through the analysis of magnetic properties, hysteresis loops for all the samples were narrow with low values of coercivity and retentivity, indicating the paramagnetic nature of these samples. And saturation magnetization Ms strongly depended on the type of additive to reach a maximum of 47.99 emu/g for x=0.015, which showed a great promise for hyperthermia applications.
基金supported by Basic Science Research through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2017R1D1A1B03035077)also supported by Research Program(2018R1A2B2006708)+1 种基金Technology Development Program to Solve Climate Changes(2015M1A2A2057062)funded by the National Research Foundation under the Ministry of Science and ICT,Republic of Koreasupported by the Defense Challengeable Future Technology Program of the Agency for Defense Development,Republic of Korea。
文摘Herein,we examine the performance of dye-sensitized solar cells containing five D-π-A organic dyes designed by systematic modification of π-bridge size and geometric structure.Each dye has a simple push-pull structure with a triarylamino group as an electron donor,bithiophene-4,4-dimethyl-4 H-cyclopenta 1,2-b:5,4-b’]dithiophene(M11),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophenethiophene(M12),thiophene-4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M13),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene-benzene(M14),and 4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M15)units asπ-bridges,and cyanoacrylic acid as an electron acceptor/anchor.The extension of theπ-bridge linkage favors wide-range absorption but,because of the concomitant molecular volume increase,hinders the efficient adsorption of dyes on the TiO_(2) film surface.Hence,higher loadings are achieved for smaller dye molecules,resulting in(i)a shift of the TiO_(2) conduction band edge to more negative values,(ii)a greater photocurrent,and(iii)suppressed charge recombination between the photoanode and the redox couple in the electrolyte.Consequently,under one-sun equivalent illumination(AM 1.5 G,100 mW/cm^(2)),the highest photovoltage,photocurrent,and conversion efficiency(η=7.19%)are observed for M15,which has the smallest molecular volume among M series dyes.
基金supported by Brain Pool program funded by the Ministry of Science and ICT through the National Research Foundation of Korea(Grant Nos.RS-2023-00284361 and 2021R1A2C2091497)supported by the Nano&Materials Technology Development Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(RS-2024-00436563)
文摘Hydrogen spillover effect has recently garnered a lot of attention in the field of electrocatalytic hydrogen evolution reactions.A new avenue for understanding the dynamic behavior of atomic migration in which hydrogen atoms moving on a catalyst surface was opened up by the setup of the word"hydrogen spillover."However,there is currently a dearth of thorough knowledge regarding the hydrogen spillover effect.Currently,the advancement of sophisticated characterization procedures offers progressively useful information to enhance our grasp of the hydrogen spillover effect.The understanding of material fabrication for hydrogen spillover effect has erupted.Considering these factors,we made an effort to review most of the articles published on the hydrogen spillover effect and carefully analyzed the aspect of material fabrication.All of our attention has been directed toward the molecular pathway that leads to improve hydrogen evolution reactions performance.In addition,we have attempted to elucidate the spillover paths through the utilization of DFT calculations.Furthermore,we provide some preliminary research suggestions and highlight the opportunities and obstacles that are still to be confronted in this study area.
基金supported by CURAM-Science Foundation Ireland(SFI)center for medical devices(Grant Number 13/RC/2073_P2)Irish Research Council Postdoctoral Fellowship(GOIPD/2021/928):Disposable,biodegradable,endoscopic ultrasonic imaging probe(DISPOSON)+1 种基金SFI Opportunistic Fund(no.12/RI/2345/SOF)is acknowledged for the NTEGRA Hybrid Nanoscope used in Piezoresponse Force MicroscopyOpen access funding provided by IReL.
文摘Eco-friendly and antimicrobial globular protein lysozyme is widely produced for several commercial applications.Interestingly,it can also be able to convert mechanical and thermal energy into electricity due to its piezo-and pyroelectric nature.Here,we demonstrate engineering of lysozyme into piezoelectric devices that can exploit the potential of lysozyme as environmentally friendly,biocompatible material for mechanical energy harvesting and sensorics,especially in micropowered electronic applications.Noteworthy that this flexible,shape adaptive devices made of crystalline lysozyme obtained from hen egg white exhibited a longitudinal piezoelectric charge coefficient(d-2.7 pC N^(-1))and piezoelectric voltage coefficient(g-76.24 mVmN^(-1))which are comparable to those of quartz(-2.3 pC N^(-1) and 50 mVmN^(-1)).Simple finger tapping on bio-organic energy harvester(BEH)made of lysozyme produced up to 350 mV peak-to-peak voltage,and a maximum instantaneous power output of 2.2 nW cm^(-2).We also demonstrated that the BEH could be used for self-powered motion sensing for real-time monitoring of different body functions.These results pave the way toward self-powered,autonomous,environmental-friendly bio-organic devices for flexible energy harvesting,storage,and in wearable healthcare monitoring.
