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
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
Supercapacitors are indispensable for next-generation energy storage,achieving high energy density and long-term durability remains a formidable challenge.Conventional CoS suffers from poor conductivity,while Ti_(3)C_...Supercapacitors are indispensable for next-generation energy storage,achieving high energy density and long-term durability remains a formidable challenge.Conventional CoS suffers from poor conductivity,while Ti_(3)C_(2)faces severe restacking.Herein,we report a novel synthesis strategy that integrates metal-organic framework(MOF)growth with electrostatic self-assembly to construct heterojunction of CoS nanotubes coated with ultrathin Ti_(3)C_(2)nanofilms.Material characterization via SEM,TEM,XRD,and XPS systematically confirms the heterostructure formation,and chemical composition.This rational design synergistically leverages CoS high pseudocapacitance and Ti_(3)C_(2)metallic conductivity while the heterostructure mitigates restacking,enhances charge transfer,and stabilizes interfacial interactions.Density functional theory(DFT)calculations reveal strengthened OH-adsorption at the Co-Ti interface(E_(ad)=1.106 eV).Consequently,the CoS/Ti_(3)C_(2)@CC delivers a remarkable specific capacitance of 1034.21 F g^(-1) at 1 A g^(-1).Assembled into a supercapacitor,CoS/Ti_(3)C_(2)@CC//AC achieves a high energy density of 74.22 Wh kg^(-1) at 800 W kg^(-1),maintaining 89.13%initial capacitance after 10,000 cycles.Significantly,it exhibits a remarkably low leakage current(0.23μA)and ultra-prolonged voltage retention(47.14%after 120 h),underscoring exceptional durability.This work pioneers a rational heterostructure engineering strategy by integrating MOF-derived architectures with conductive MXene nanofilms,offering critical insights for the development of ultra-durable supercapacitors.展开更多
A kind of photoelectrode was innovated by anodising titanium mesh in H 2SO 4 solution and photo reduced in HAuCl 4 solution and named Ti/Au TiO 2 mesh electrode. The structural and surface morphology of the Ti/Au TiO ...A kind of photoelectrode was innovated by anodising titanium mesh in H 2SO 4 solution and photo reduced in HAuCl 4 solution and named Ti/Au TiO 2 mesh electrode. The structural and surface morphology of the Ti/Au TiO 2 mesh was examined by X ray diffraction, laser Raman spectra, scanning electronic microscopy(SEM) and X ray photoelectron spectroscopy respectively. The results indicate that its crystal structure, morphology and the size of pore are affected greatly by gold deposition. XPS measurement shows that the valence band of Ti/TiO 2 has two peaks: a wide one at 4.97 eV and a narrow one at 6.61 eV, which correspond mainly to π(nonbonding) and σ (bonding) O 2p orbitals. The emission intensity of O 2p orbitals becomes stronger and the width of the valence band increases with the increase of Au content. And the emission of nonbonding shifts toward lower binding energy and that of bonding O 2p orbitals shifts toward higher binding energy. The photoelectrocatalytic(PEC) oxidation of humic acid(HA) was investigated in terms of TOC. The PEC oxidation efficiency of Ti/Au TiO 2 mesh with optimal content of gold is higher than that of Ti/TiO 2 mesh. It is suggested that the recombination of electrons and holes is hindered owing to gold deposition. The investigation shows that PEC oxidation is a convenient way to mineralize organic matter for water treatment.展开更多
A transparent phase-pure anatase TiO_(2)nanofilm was prepared through magnetron sputtering method,and a subsequent annealing treatment awarded it the superhydrophilic characteristic.To make clear the mechanism of the ...A transparent phase-pure anatase TiO_(2)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
This paper reports that single-layer and graded Au-TiO2 granular composite films with Au atom content 15%- 66% were prepared by using reactive co-sputtering technique. The third-order optical nonlinearity of single-la...This paper reports that single-layer and graded Au-TiO2 granular composite films with Au atom content 15%- 66% were prepared by using reactive co-sputtering technique. The third-order optical nonlinearity of single-layer and graded composite films was investigated by using s- and p-polarized Z-scans in femtosecond time scale. The nonlinear absorption coefficient βeff of single-layer Au-TiO2 films is measured to be -2.3×10^3-0.76×10^3 cm/GW with Au atom content 15%-66%. The βeff value of the 10-layer Au-TiO2 graded film is enhanced to be -2.1×10^4cm/GW calculated from p-polarized Z-scans, which is about ten times the maximum βeff of single-layer films. Broadened response in the wavelength region 730-860 nm of the enhanced optical nonlinearity of graded Au-TiO2 composite films was also investigated.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 National Natural Science Foundation of China(22201107,52203147)Zhejiang Provincial Natural Science Foundation of China(MS25B040011)significant science and technology projects of LongMen Laboratory in Henan Province(231100220100).
文摘Supercapacitors are indispensable for next-generation energy storage,achieving high energy density and long-term durability remains a formidable challenge.Conventional CoS suffers from poor conductivity,while Ti_(3)C_(2)faces severe restacking.Herein,we report a novel synthesis strategy that integrates metal-organic framework(MOF)growth with electrostatic self-assembly to construct heterojunction of CoS nanotubes coated with ultrathin Ti_(3)C_(2)nanofilms.Material characterization via SEM,TEM,XRD,and XPS systematically confirms the heterostructure formation,and chemical composition.This rational design synergistically leverages CoS high pseudocapacitance and Ti_(3)C_(2)metallic conductivity while the heterostructure mitigates restacking,enhances charge transfer,and stabilizes interfacial interactions.Density functional theory(DFT)calculations reveal strengthened OH-adsorption at the Co-Ti interface(E_(ad)=1.106 eV).Consequently,the CoS/Ti_(3)C_(2)@CC delivers a remarkable specific capacitance of 1034.21 F g^(-1) at 1 A g^(-1).Assembled into a supercapacitor,CoS/Ti_(3)C_(2)@CC//AC achieves a high energy density of 74.22 Wh kg^(-1) at 800 W kg^(-1),maintaining 89.13%initial capacitance after 10,000 cycles.Significantly,it exhibits a remarkably low leakage current(0.23μA)and ultra-prolonged voltage retention(47.14%after 120 h),underscoring exceptional durability.This work pioneers a rational heterostructure engineering strategy by integrating MOF-derived architectures with conductive MXene nanofilms,offering critical insights for the development of ultra-durable supercapacitors.
文摘A kind of photoelectrode was innovated by anodising titanium mesh in H 2SO 4 solution and photo reduced in HAuCl 4 solution and named Ti/Au TiO 2 mesh electrode. The structural and surface morphology of the Ti/Au TiO 2 mesh was examined by X ray diffraction, laser Raman spectra, scanning electronic microscopy(SEM) and X ray photoelectron spectroscopy respectively. The results indicate that its crystal structure, morphology and the size of pore are affected greatly by gold deposition. XPS measurement shows that the valence band of Ti/TiO 2 has two peaks: a wide one at 4.97 eV and a narrow one at 6.61 eV, which correspond mainly to π(nonbonding) and σ (bonding) O 2p orbitals. The emission intensity of O 2p orbitals becomes stronger and the width of the valence band increases with the increase of Au content. And the emission of nonbonding shifts toward lower binding energy and that of bonding O 2p orbitals shifts toward higher binding energy. The photoelectrocatalytic(PEC) oxidation of humic acid(HA) was investigated in terms of TOC. The PEC oxidation efficiency of Ti/Au TiO 2 mesh with optimal content of gold is higher than that of Ti/TiO 2 mesh. It is suggested that the recombination of electrons and holes is hindered owing to gold deposition. The investigation shows that PEC oxidation is a convenient way to mineralize organic matter for water treatment.
基金National Nature Science Foundation of China(50705094)
文摘A transparent phase-pure anatase TiO_(2)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Project supported by the National Natural Science Foundation of China (Grant No 10474075)
文摘This paper reports that single-layer and graded Au-TiO2 granular composite films with Au atom content 15%- 66% were prepared by using reactive co-sputtering technique. The third-order optical nonlinearity of single-layer and graded composite films was investigated by using s- and p-polarized Z-scans in femtosecond time scale. The nonlinear absorption coefficient βeff of single-layer Au-TiO2 films is measured to be -2.3×10^3-0.76×10^3 cm/GW with Au atom content 15%-66%. The βeff value of the 10-layer Au-TiO2 graded film is enhanced to be -2.1×10^4cm/GW calculated from p-polarized Z-scans, which is about ten times the maximum βeff of single-layer films. Broadened response in the wavelength region 730-860 nm of the enhanced optical nonlinearity of graded Au-TiO2 composite films was also investigated.
