Two-dimensional(2D)noble transition-metal dichalcogenide materials(NTMDs)have garnered remarkable attention due to their intriguing properties exhibiting potential applications in nanoelectronics,optoelectronics,and p...Two-dimensional(2D)noble transition-metal dichalcogenide materials(NTMDs)have garnered remarkable attention due to their intriguing properties exhibiting potential applications in nanoelectronics,optoelectronics,and photonics.The electronic structure and physical properties of 2D NTMDs can be effectively modulated using alloy engineering strategy.Nevertheless,the precise growth of wafer-scale 2D NTMDs alloys remains a significant challenge.In this work,we have achieved the controllable preparation of wafer-scale(2-inch)2D PdS_(2x)Se_(2(1-x)) nanofilms(NFs)with fully tunable compositions on various substrates using pre-deposited Pd NFs assisted chemical vapor deposition technique.High-performance photodetectors based on the PdS_(2x)Se_(2(1-x))NFs were fabricated,which exhibit broadband photodetection performance from visible to near-infrared(NIR)wavelength range at room temperature.Significantly,the PdS0.9Se1.1-based photodetectors display a responsivity up to 0.192 A W^(-1) and a large specific detectivity of 5.5×1011 Jones for 850 nm light,enabling an excellent high-resolution NIR single-pixel imaging(SPI)without an additional filtering circuit.Our work paves a new route for the controlled synthesis of wafer-scale and high-quality 2D NTMDs alloy NFs,which is essential for designing advanced optoelectronic devices.展开更多
A transparent phase-pure anatase TiO2 nanofilm was prepared through magnetron sputtering method,and a subsequent annealing treatment awarded it the superhydrophilic characteristic.To make clear the mechanism of the he...A transparent phase-pure anatase TiO2 nanofilm was prepared through magnetron sputtering method,and a subsequent annealing treatment awarded it the superhydrophilic characteristic.To make clear the mechanism of the heat-induced superhydrophilicity,the chemical composition and surface morphology of the film were investigated in detail and compared before and after the annealing treatment mainly by field emission scanning electron microscopy(FESEM),X-ray diffraction method(XRD),Raman spectroscopy,and X-ray photoelectron spectroscope(XPS).The results suggest that the probable mechanism is in accordance with the UV-induced mechanism,where the heat-induced surface oxygen vacancies and hydroxyl radicals play important roles for achieving the superhydrophilicity.展开更多
Palladium(Pd)-based sulfides have triggered extensive interest due to their unique properties and potential applications in the fields of electronics and optoelectronics.However,the synthesis of large-scale uniform Pd...Palladium(Pd)-based sulfides have triggered extensive interest due to their unique properties and potential applications in the fields of electronics and optoelectronics.However,the synthesis of large-scale uniform PdS and PdS_(2)nanofilms(NFs)remains an enormous challenge.In this work,2-inch wafer-scale PdS and PdS_(2) NFs with excellent stability can be controllably prepared via chemical vapor deposition combined with electron beam evaporation technique.The thickness of the pre-deposited Pd film and the sulfurization temperature are critical for the precise synthesis of PdS and PdS_(2) NFs.A corresponding growth mechanism has been proposed based on our experimental results and Gibbs free energy calculations.The electrical transport properties of PdS and PdS_(2) NFs were explored by conductive atomic force microscopy.Our findings have achieved the controllable growth of PdS and PdS_(2) NFs,which may provide a pathway to facilitate PdS and PdS_(2) based applications for next-generation high performance optoelectronic devices.展开更多
The low-temperature physical vapor deposition process of atomically thin two-dimensional transition metal dichalcogenide(2D TMD) has been gaining attention owing to the cost-effective production of diverse electrochem...The low-temperature physical vapor deposition process of atomically thin two-dimensional transition metal dichalcogenide(2D TMD) has been gaining attention owing to the cost-effective production of diverse electrochemical catalysts for hydrogen evolution reaction(HER) applications. We, herein, propose a simple route toward the cost-effective physical vapor deposition process of 2D WSe2 layered nanofilms as HER electrochemical catalysts using RF magnetron sputtering at room temperature(<27℃). By controlling the variable sputtering parameters, such as RF power and deposition time, the loading amount and electrochemical surface area(ECSA) of WSe2 films deposited on carbon paper can be carefully determined. The surface of the sputtered WSe2 films are partially oxidized, which may cause spherical-shaped particles. Regardless of the loading amount of WSe2, Tafel slopes of WSe2 electrodes in the HER test are narrowly distributed to be ~120–138 mV dec-1, which indicates the excellent reproducibility of intrinsic catalytic activity. By considering the trade-off between the loading amount and ECSA, the best HER performance is clearly observed in the 200 W-15 min sample with an overpotential of 220 mV at a current density of 10 mA cm-2. Such a simple sputtering method at low temperature can be easily expanded to other 2D TMD electrochemical catalysts, promising potentially practical electrocatalysts.展开更多
Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays （TINT） were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were pr...Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays （TINT） were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were prepared by home-made Metal Vapor Vacuum Arc ions sources （MEVVA, BNU, China） implanter. Photo-electric response and methyl orange decomposition ability of implanted samples under UV and visible light were tested, and the results indicated that the performance of Cu/TiNT enhanced significantly under visible light; it was noteworthy that the photocurrent density of A-Cu/TiNT was 0.102 mA/cm^2, which was 115 times that of pure TINT, and degradation ability of TiNT also strongly enhanced under visible light. In a word, the absorption spectrum of implanted anatase titania shifted to a longer wavelength region. Theoretic study on Cu-doped anatase based on density functional theory was carried out in this paper to validate the experiment results. The calculation results are depicted as follows： Intermittent energy band appeared around the Fermi energy after doping with Cu metal, the width of which was 0.35 eV and the location of valence and conduction bands shifted to the lower energy level by 0.22 eV; more excitation and jump routes were opened for the electrons. The narrowed band gaps allowed the photons with lower energy （at longer wavelength, such as visible light） to be absorbed, which accorded well with the experimental results.展开更多
Novel large-sized mesoporous nanofilm-constructed macroporous SiO2(LMNCMS)with two sets of well-defined 3D continuous pass-through macropores(pore size of 0.5-1.0 um,wall thickness of 40-50 nm)was prepared through a d...Novel large-sized mesoporous nanofilm-constructed macroporous SiO2(LMNCMS)with two sets of well-defined 3D continuous pass-through macropores(pore size of 0.5-1.0 um,wall thickness of 40-50 nm)was prepared through a dual-templating approach,and used as an advanced support for TiO2 nanocrystalline photocatalyst.The structural and optical properties of the as-prepared materials were investigated by various characterization techniques in order to explore the connections between catalysts'features and catalytic performance.The photocatalytic activities were evaluated by degradations of methylene blue(MB)and phenol under the simulated sunlight irradiation.To gain insight into the impact of preparation and operation conditions on photocatalytic degradation processes,experiments were conducted at wide ranges of the TiO2 loading content,calcination temperature,solution pH,and photocatalyst dosage.Nano-TiO2/LMNCMS exhibited high photocatalytic activity and stability.Rapid matter transport,good access ibility of pollutants to TiO2 and high light harvesting could mainly account for the superior photocatalytic performance.The trapping experiments were performed to identify the main reactive species in the catalytic reactions.展开更多
The electrocatalytic reduction of CO_(2)is a promising pathway to generate renewable fuels and chemicals.However,its advancement is impeded by the absence of electrocatalysts with both high selectivity and stability.H...The electrocatalytic reduction of CO_(2)is a promising pathway to generate renewable fuels and chemicals.However,its advancement is impeded by the absence of electrocatalysts with both high selectivity and stability.Here,we present a scalable in-situ thermal evaporation technique for synthesizing series of Bi,In,and Sn nanofilms on carbon felt(CF)substrates with a high-aspect-ratio structure.The resulting main-group metal nanofilms exhibit a homogeneously distributed and highly exposed catalyst surface with ample active sites,thereby promoting mass transport and ad-/desorption of reaction intermediates.Benefiting from the unique fractal morphology,the Bi nanofilms deposited on CF exhibit optimal catalytic activities for CO_(2)electroreduction among the designed metal nanofilms electrodes,with the highest Faradaic efficiency of 96.9%for formate production at−1.3 V vs.reversible hydrogen electrode(RHE)in H-cell.Under an industrially relevant current density of 221.4 mA·cm−2 in flow cells,the Bi nanofilms retain a high Faradaic efficiency of 81.7%at−1.1 V(vs.RHE)and a good long-term stability for formate production.Furthermore,a techno-economic analysis(TEA)model shows the potential commercial viability of electrocatalytic CO_(2)conversion into formate using the Bi nanofilms catalyst.Our results offer a green and convenient approach for in-situ fabrication of stable and inexpensive thin-film catalysts with a fractal structure applicable to various industrial settings.展开更多
The unique multilayer, multiscale structure of teakwood results in excellent mechanical and long-term environmental stability, providing inspiration for the biomimetic design of environmental barrier coating (EBC) str...The unique multilayer, multiscale structure of teakwood results in excellent mechanical and long-term environmental stability, providing inspiration for the biomimetic design of environmental barrier coating (EBC) structures. However, achieving the desired biomimetic structure control in high-temperature plasma spraying is a challenging task that requires new technological breakthroughs. In this study, a multiscale nano Yb_(2)Si_(2)O_(7)–Yb_(2)SiO_(5) (YbDS–YbMS) composite EBC with a teakwood-like lamellar structure was realized via a novel alternating vapor/liquid phase deposition method involving plasma spraying-physical vapor deposition (PS-PVD). Volatilized waste SiO_(2) from Yb_(2)Si_(2)O_(7) (YbDS) was reused and deposited on the coating surface during the spraying process, where a regularly arranged multilayer structure was formed in the coating by the alternate deposition of gaseous SiO_(2) and droplet YbDS. In addition, SiO_(2) on the coated surface formed nanoclusters and dome-shaped nanocrystals via homogeneous and heterogeneous nucleation, respectively, and some of them gradually formed a continuous nanofilm as the arc current increased. The deposited SiO_(2) reacted in situ with the decomposed phase YbMS in the coating to form YbDS, preserving its multiscale nanostructure after heat treatment and enabling the preparation of the YbDS–YbMS composite coating. This work provides a new design strategy and method for the preparation of coatings using YbDS and other spray powders with similar decomposition and volatilization characteristics during the plasma spraying process.展开更多
基金supported by Open Research Fund of Songshan Lake Materials Laboratory(No.2023SLABFK08)Key Research and Development Program of Hunan Province(No.2022GK2007)+2 种基金Key Project from Department Education of Hunan Province(No.22A0123)National Natural Science Foundation of China(No.11974301)Graduate Student Research Innovation of Xi-angtan University(No.XDCX2024Y198).
文摘Two-dimensional(2D)noble transition-metal dichalcogenide materials(NTMDs)have garnered remarkable attention due to their intriguing properties exhibiting potential applications in nanoelectronics,optoelectronics,and photonics.The electronic structure and physical properties of 2D NTMDs can be effectively modulated using alloy engineering strategy.Nevertheless,the precise growth of wafer-scale 2D NTMDs alloys remains a significant challenge.In this work,we have achieved the controllable preparation of wafer-scale(2-inch)2D PdS_(2x)Se_(2(1-x)) nanofilms(NFs)with fully tunable compositions on various substrates using pre-deposited Pd NFs assisted chemical vapor deposition technique.High-performance photodetectors based on the PdS_(2x)Se_(2(1-x))NFs were fabricated,which exhibit broadband photodetection performance from visible to near-infrared(NIR)wavelength range at room temperature.Significantly,the PdS0.9Se1.1-based photodetectors display a responsivity up to 0.192 A W^(-1) and a large specific detectivity of 5.5×1011 Jones for 850 nm light,enabling an excellent high-resolution NIR single-pixel imaging(SPI)without an additional filtering circuit.Our work paves a new route for the controlled synthesis of wafer-scale and high-quality 2D NTMDs alloy NFs,which is essential for designing advanced optoelectronic devices.
基金National Nature Science Foundation of China(50705094)
文摘A transparent phase-pure anatase TiO2 nanofilm was prepared through magnetron sputtering method,and a subsequent annealing treatment awarded it the superhydrophilic characteristic.To make clear the mechanism of the heat-induced superhydrophilicity,the chemical composition and surface morphology of the film were investigated in detail and compared before and after the annealing treatment mainly by field emission scanning electron microscopy(FESEM),X-ray diffraction method(XRD),Raman spectroscopy,and X-ray photoelectron spectroscope(XPS).The results suggest that the probable mechanism is in accordance with the UV-induced mechanism,where the heat-induced surface oxygen vacancies and hydroxyl radicals play important roles for achieving the superhydrophilicity.
基金supported by National Natural Science Foundation of China (No.11974301)Key Research and Development Program of Hunan Province (No.2022GK2007)+2 种基金Key Project from Department Education of Hunan Province (No.22A0123)Scientific Research Fund of Hunan Provincial Education Department (No.21B0136)National college students innovation and entrepreneurship training program (No.S202310530016)。
文摘Palladium(Pd)-based sulfides have triggered extensive interest due to their unique properties and potential applications in the fields of electronics and optoelectronics.However,the synthesis of large-scale uniform PdS and PdS_(2)nanofilms(NFs)remains an enormous challenge.In this work,2-inch wafer-scale PdS and PdS_(2) NFs with excellent stability can be controllably prepared via chemical vapor deposition combined with electron beam evaporation technique.The thickness of the pre-deposited Pd film and the sulfurization temperature are critical for the precise synthesis of PdS and PdS_(2) NFs.A corresponding growth mechanism has been proposed based on our experimental results and Gibbs free energy calculations.The electrical transport properties of PdS and PdS_(2) NFs were explored by conductive atomic force microscopy.Our findings have achieved the controllable growth of PdS and PdS_(2) NFs,which may provide a pathway to facilitate PdS and PdS_(2) based applications for next-generation high performance optoelectronic devices.
基金supported by the Fundamental Research Program of the Korean Institute of Materials Science(Grant PNK6130)the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT,Ministry of Science and ICT)(No.2017R1C1B1005076)+1 种基金financially supported by the Ministry of Trade,Industry and Energy(MOTIE)Korea Institute for Advancement of Technology(KIAT)through the National Innovation Cluster R&D program(P0006704_Development of energy saving advanced parts)。
文摘The low-temperature physical vapor deposition process of atomically thin two-dimensional transition metal dichalcogenide(2D TMD) has been gaining attention owing to the cost-effective production of diverse electrochemical catalysts for hydrogen evolution reaction(HER) applications. We, herein, propose a simple route toward the cost-effective physical vapor deposition process of 2D WSe2 layered nanofilms as HER electrochemical catalysts using RF magnetron sputtering at room temperature(<27℃). By controlling the variable sputtering parameters, such as RF power and deposition time, the loading amount and electrochemical surface area(ECSA) of WSe2 films deposited on carbon paper can be carefully determined. The surface of the sputtered WSe2 films are partially oxidized, which may cause spherical-shaped particles. Regardless of the loading amount of WSe2, Tafel slopes of WSe2 electrodes in the HER test are narrowly distributed to be ~120–138 mV dec-1, which indicates the excellent reproducibility of intrinsic catalytic activity. By considering the trade-off between the loading amount and ECSA, the best HER performance is clearly observed in the 200 W-15 min sample with an overpotential of 220 mV at a current density of 10 mA cm-2. Such a simple sputtering method at low temperature can be easily expanded to other 2D TMD electrochemical catalysts, promising potentially practical electrocatalysts.
基金Supported by the National Natural Science Foundation of China (No. 10975020)Key Laboratory of BeamTechnology and Material Modification of Ministry of Education, Beijing Normal University
文摘Highly oxidation. SEM analysis ordered anatase titania nanotube method was used to characterize arrays （TINT） were fabricated by anodic the morphology of the prepared samples. TiNT samples doped with Cu ions were prepared by home-made Metal Vapor Vacuum Arc ions sources （MEVVA, BNU, China） implanter. Photo-electric response and methyl orange decomposition ability of implanted samples under UV and visible light were tested, and the results indicated that the performance of Cu/TiNT enhanced significantly under visible light; it was noteworthy that the photocurrent density of A-Cu/TiNT was 0.102 mA/cm^2, which was 115 times that of pure TINT, and degradation ability of TiNT also strongly enhanced under visible light. In a word, the absorption spectrum of implanted anatase titania shifted to a longer wavelength region. Theoretic study on Cu-doped anatase based on density functional theory was carried out in this paper to validate the experiment results. The calculation results are depicted as follows： Intermittent energy band appeared around the Fermi energy after doping with Cu metal, the width of which was 0.35 eV and the location of valence and conduction bands shifted to the lower energy level by 0.22 eV; more excitation and jump routes were opened for the electrons. The narrowed band gaps allowed the photons with lower energy （at longer wavelength, such as visible light） to be absorbed, which accorded well with the experimental results.
基金This work was financially supported by the Science and Technology Benefiting Projects of Ningbo(Grant No.2017C50033),the Public Projects of Zhejiang Province(Grant No.LGG19E020002),and the KC Wong Happiness Fund in Ningbo University.
文摘Novel large-sized mesoporous nanofilm-constructed macroporous SiO2(LMNCMS)with two sets of well-defined 3D continuous pass-through macropores(pore size of 0.5-1.0 um,wall thickness of 40-50 nm)was prepared through a dual-templating approach,and used as an advanced support for TiO2 nanocrystalline photocatalyst.The structural and optical properties of the as-prepared materials were investigated by various characterization techniques in order to explore the connections between catalysts'features and catalytic performance.The photocatalytic activities were evaluated by degradations of methylene blue(MB)and phenol under the simulated sunlight irradiation.To gain insight into the impact of preparation and operation conditions on photocatalytic degradation processes,experiments were conducted at wide ranges of the TiO2 loading content,calcination temperature,solution pH,and photocatalyst dosage.Nano-TiO2/LMNCMS exhibited high photocatalytic activity and stability.Rapid matter transport,good access ibility of pollutants to TiO2 and high light harvesting could mainly account for the superior photocatalytic performance.The trapping experiments were performed to identify the main reactive species in the catalytic reactions.
基金the National Key Research and Development Program of China(No.2017YFA0208200)the National Natural Science Foundation of China(Nos.22022505 and 21872069)+5 种基金the Fundamental Research Funds for the Central Universities of China(Nos.020514380266,020514380272,and 020514380274)the General Project of the Joint Fund of Equipment Pre-research and the Ministry of Education(No.8091B02052407)the Scientific and Technological Achievements Transformation Special Fund of Jiangsu Province(No.BA2023037)the Scientific and Technological Innovation Special Fund for Carbon Peak and Carbon Neutrality of Jiangsu Province(No.BK20220008)the Nanjing International Collaboration Research Program(Nos.202201007 and 2022SX00000955)the Suzhou Gusu Leading Talent Program of Science and Technology Innovation and Entrepreneurship in Wujiang District(No.ZXL2021273).
文摘The electrocatalytic reduction of CO_(2)is a promising pathway to generate renewable fuels and chemicals.However,its advancement is impeded by the absence of electrocatalysts with both high selectivity and stability.Here,we present a scalable in-situ thermal evaporation technique for synthesizing series of Bi,In,and Sn nanofilms on carbon felt(CF)substrates with a high-aspect-ratio structure.The resulting main-group metal nanofilms exhibit a homogeneously distributed and highly exposed catalyst surface with ample active sites,thereby promoting mass transport and ad-/desorption of reaction intermediates.Benefiting from the unique fractal morphology,the Bi nanofilms deposited on CF exhibit optimal catalytic activities for CO_(2)electroreduction among the designed metal nanofilms electrodes,with the highest Faradaic efficiency of 96.9%for formate production at−1.3 V vs.reversible hydrogen electrode(RHE)in H-cell.Under an industrially relevant current density of 221.4 mA·cm−2 in flow cells,the Bi nanofilms retain a high Faradaic efficiency of 81.7%at−1.1 V(vs.RHE)and a good long-term stability for formate production.Furthermore,a techno-economic analysis(TEA)model shows the potential commercial viability of electrocatalytic CO_(2)conversion into formate using the Bi nanofilms catalyst.Our results offer a green and convenient approach for in-situ fabrication of stable and inexpensive thin-film catalysts with a fractal structure applicable to various industrial settings.
基金support from the National Natural Science Foundation of China(Nos.52322104,52172067,and 92160202)the Natural Science Foundation of Guangdong Province(No.2021B1515020038)+2 种基金the Guangdong Special Support Program(No.2019BT02C629)the Guangdong Provincial Science and Technology Program(No.2023A0505010017)the Science Center for Gas Turbine Project(No.P2023-C-IV-002-001).
文摘The unique multilayer, multiscale structure of teakwood results in excellent mechanical and long-term environmental stability, providing inspiration for the biomimetic design of environmental barrier coating (EBC) structures. However, achieving the desired biomimetic structure control in high-temperature plasma spraying is a challenging task that requires new technological breakthroughs. In this study, a multiscale nano Yb_(2)Si_(2)O_(7)–Yb_(2)SiO_(5) (YbDS–YbMS) composite EBC with a teakwood-like lamellar structure was realized via a novel alternating vapor/liquid phase deposition method involving plasma spraying-physical vapor deposition (PS-PVD). Volatilized waste SiO_(2) from Yb_(2)Si_(2)O_(7) (YbDS) was reused and deposited on the coating surface during the spraying process, where a regularly arranged multilayer structure was formed in the coating by the alternate deposition of gaseous SiO_(2) and droplet YbDS. In addition, SiO_(2) on the coated surface formed nanoclusters and dome-shaped nanocrystals via homogeneous and heterogeneous nucleation, respectively, and some of them gradually formed a continuous nanofilm as the arc current increased. The deposited SiO_(2) reacted in situ with the decomposed phase YbMS in the coating to form YbDS, preserving its multiscale nanostructure after heat treatment and enabling the preparation of the YbDS–YbMS composite coating. This work provides a new design strategy and method for the preparation of coatings using YbDS and other spray powders with similar decomposition and volatilization characteristics during the plasma spraying process.
