MnO2-impregnated carbon-coated Fe3 O4(Fe3O4/C/MnO2)nanocomposites with a good core-shell structure were prepared by direct oxidation of carbon-coated Fe3 O4(Fe3O4/C)microspheres with KMnO4 in alkaline solution and app...MnO2-impregnated carbon-coated Fe3 O4(Fe3O4/C/MnO2)nanocomposites with a good core-shell structure were prepared by direct oxidation of carbon-coated Fe3 O4(Fe3O4/C)microspheres with KMnO4 in alkaline solution and applied to adsorb bovine serum albumin(BSA).X-ray diffraction(XRD),transmission electron microscope(TEM),Fourier transform infrared spectrometer(FTIR),vibrating sample magnetometer(VSM)and thermogravimetric analyzer(TGA)tests show that Fe3O4/C microspheres were newly functionalized via the oxidation by KMnO4.Fe3O4/C/MnO2 nanocomposites exhibit a higher adsorption capacity for BSA than Fe3O4/C microspheres and the maximum adsorption of BSA on them occurs at pH 4.7,which is the isoelectric point of BSA.Langmuir isotherm model describes the adsorption of BSA better than Freundlich model and Temkin model,and the kinetics data fit well with the pseudo-second-order model.展开更多
In order to achieve combined mechanical and electrical properties,multi-walled carbon nanotubes(MWCNTs)reinforced Cu/Ti_(3)SiC_(2)/C nanocomposites were further processed by high-pressure torsion(HPT).The maximum micr...In order to achieve combined mechanical and electrical properties,multi-walled carbon nanotubes(MWCNTs)reinforced Cu/Ti_(3)SiC_(2)/C nanocomposites were further processed by high-pressure torsion(HPT).The maximum microhardness values of central and edge from the composites with 1 wt.%MWCNTs reached HV 130.0 and HV 363.5,which were 43.9%and 39.5%higher than those of the original samples,respectively.With the same content of MWCNTs,its electrical conductivity achieved 3.42×10^(7) S/m,which was increased by 78.1%compared with that of original samples.The synergistic improvement of mechanical and electrical properties is attributed to the obtained microstructure with increased homogenization and refinement,as well as improved interfacial bonding and reduced porosity.The strengthening mechanisms include dispersion and refinement strengthening for mechanical properties,as well as reduced electron scattering for electrical properties.展开更多
A simple, mild and green approach has been developed for the synthesis of asymmetrical heterobiaryls under the irradiation of visible light without any oxidants and promoting reagents through using Pd/Ce O2 nanocompos...A simple, mild and green approach has been developed for the synthesis of asymmetrical heterobiaryls under the irradiation of visible light without any oxidants and promoting reagents through using Pd/Ce O2 nanocomposite photocatalyst. This method can tolerate considerable functional groups such as electrondonating groups and electron-withdrawing groups through CààC cross-coupling. Moreover, we obtain the products with moderate yields in an efficient way. Finally, a plausible mechanism is proposed.展开更多
A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R...A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R lines in the fluorescence spectra va ry with the distance from the centre of indentation. The magnitude of load appli ed on the surface of the materials through the indenter influences the shifts of R lines to great extent. The luminescence of R lines of the materials before indenting is used to determine the residual stresses around the indentation in the materials, assuming that the stress tensor is transversely isotropic. Final ly, the term of hydrostatic stress is adopted to explain and compare different residual stresses around indentations with the increase of the indenting load an d the distance from the centre of indentations. <展开更多
A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R...A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R lines in the fluorescence spectra va ry with the distance from the centre of indentation. The magnitude of load appli ed on the surface of the materials through the indenter influences the shifts of R lines to great extent. The luminescence of R lines of the materials before indenting is used to determine the residual stresses around the indentation in the materials, assuming that the stress tensor is transversely isotropic. Final ly, the term of hydrostatic stress is adopted to explain and compare different residual stresses around indentations with the increase of the indenting load an d the distance from the centre of indentations. 【展开更多
Tin sulfide nanoparticles(SnS -NPs) were prepared in aqueous solution at room temperature on the surface of activated carbon(AC) and were investigated using field-emission scanning electron mi-croscopy(FE-SEM), transm...Tin sulfide nanoparticles(SnS -NPs) were prepared in aqueous solution at room temperature on the surface of activated carbon(AC) and were investigated using field-emission scanning electron mi-croscopy(FE-SEM), transmission electron microscopy(TEM), X-ray diffraction, reflective ultravio-let-visible spectrophotometry, and spectrofluorimetry. Calculations based on the SEM and TEM images showed that the sizes of the SnS -NPs immobilized on the AC were 30–70 nm. The prepared nanocomposite was used as a heterogeneous Lewis acid catalyst for the three-components one-pot synthesis of 4H-pyrano[2,3-c]pyrazole derivatives in ethanol at 80 ℃. The reactions were efficiently performed in the presence of the prepared catalyst in short reaction times, and gave the desired products in high yields. This catalyst can be easily recovered by simple filtration and recycled up to eight consecutive times without significant loss of its efficiency.展开更多
为获得一种具有理论容量高、循环性能佳、光催化性能优异的新型多功能材料,在石墨存在下,以钛酸四丁酯为钛源,利用简单的一步溶剂热法制备不同石墨含量的石墨@TiO_(2)复合材料并对其进行表征。将石墨@TiO_(2)复合材料作为锂离子电池负...为获得一种具有理论容量高、循环性能佳、光催化性能优异的新型多功能材料,在石墨存在下,以钛酸四丁酯为钛源,利用简单的一步溶剂热法制备不同石墨含量的石墨@TiO_(2)复合材料并对其进行表征。将石墨@TiO_(2)复合材料作为锂离子电池负极材料测试了其电化学性能,并将其用作降解甲基橙溶液的光催化剂测试了其光催化性能。结果表明:锐钛矿型TiO_(2)纳米线呈三维相互交织状包覆在石墨片表面,使复合材料具有较高的比表面积;复合材料中TiO_(2)含量越高,其初始放电比容量越大,在100 mA/g电流密度下的初始放电比容量最高可达到464.9 m A·h/g,在2 A/g电流密度下的初始放电比容量最高可达到120.3 mA·h/g;而复合材料中TiO_(2)含量越低,其可逆循环性能越好,在100 m A/g电流密度下循环100次后放电比容量为310.8 mA·h/g;石墨@TiO_(2)复合材料光催化性能随着TiO_(2)含量的增加而增强,在紫外光照射60 min后,甲基橙溶液的降解率最高可达98.72%。研究表明,石墨@TiO_(2)复合材料具有优异的电化学性能和光催化性能,有望替代传统的负极材料和光催化剂材料,具有广阔的应用前景。展开更多
Triboelectric nanogenerator(TENG)can realize a variety of mechanical energy collections in the environment,which has great potential in the field of wearable energy.However,many TENGs could rarely be satisfactory to w...Triboelectric nanogenerator(TENG)can realize a variety of mechanical energy collections in the environment,which has great potential in the field of wearable energy.However,many TENGs could rarely be satisfactory to wearable electronics promotion because of their expensive raw materials and complex manufacturing processes.In this study,a type of porous structure carbon powder/manganese dioxide(C/MnO_(2))nanocomposite is introduced.The material adopts low-cost,high-yield carbon powder,can be prepared in one step through a simple,economical,and environmentally friendly hydrothermal preparation process,and has high economic practicality.Superior power generation performance was obtained by modulating the charge trapping ability and storage capacity of polydimethylsiloxane@C/MnO_(2)(PDMS@C/MnO_(2))film based on variations in the weight-loading of C/MnO_(2).The maximum output voltage of carbon powder/manganese dioxide TENG(CM-TENG)is 63 V,which is 2.1 times that of PDMS-TENG and 1.86 times that of carbon powder TENG(C-TENG)and can easily light up 53 LEDs.Furthermore,CM-TENG can convert biological motion energy into electrical signals to detect human hand movements.The CM-TENG self-powered system can successfully drive various microelectronic devices,such as electronic watches,liquid crystal displays(LCDs),and calculators.This study provides a reliable,low-cost,high-performance,and widely applicable electronic system that shows great potential in future fields such as wearable devices and micro-sensing systems.展开更多
The key to solve increasingly severe electromagnetic(EM)pollution is to explore sustainable,easily prepared,and cost-effective EM wave absorption materials with exceptional absorption capability.Herein,instead of anch...The key to solve increasingly severe electromagnetic(EM)pollution is to explore sustainable,easily prepared,and cost-effective EM wave absorption materials with exceptional absorption capability.Herein,instead of anchoring on carbon materials in single layer,MoS_(2) flower-like microspheres were stacked on the surface of pomelo peels-derived porous carbon nanosheets(C)to fabricate MoS_(2)@C nanocomposites by a facile solvothermal process.EM wave absorption performances of MoS_(2)@C nanocomposites in X-band were systematically investigated,indicating the minimum reflection loss(RLmin)of-62.3 dB(thickness of 2.88 mm)and effective absorption bandwidth(EAB)almost covering the whole X-band(thickness of 2.63 mm)with the filler loading of only 20 wt.%.Superior EM wave absorption performances of MoS_(2)@C nanocomposites could be attributed to the excellent impedance matching characteristic and dielectric loss capacity(conduction loss and polarization loss).This study revealed that the as-prepared MoS_(2)@C nanocomposites would be a novel prospective candidate for the sustainable EM absorbents with superior EM wave absorption performances.展开更多
Molybdenum disulfide(MoS_(2)) films are widely deployed in industrial applications owing to their inherent interlayer slip characteristics, offering energy consumption savings and prolonged mechanical part performance...Molybdenum disulfide(MoS_(2)) films are widely deployed in industrial applications owing to their inherent interlayer slip characteristics, offering energy consumption savings and prolonged mechanical part performance. Nevertheless, their practical utility is limited by environmental constraints and the limitations of preparation techniques, which hinder the attainment of robust superlubricity(friction coefficient < 0.01). Herein, through magnetron sputtering technology, we synthesize a core-shell-like nanocomposite composed of MoS_(2)nanosheets encapsulating B_(4)C. The core-shell-like structure enables the resulting films to preferentially grow crystalline MoS_(2), providing them with outstanding mechanical properties and efficient lubrication over a wide range of temperatures. Remarkably, such film achieves robust macroscale superlubricity and an ultralow wear rate(1.7 ×10^(-8)mm^(3)N-1m^(-1)) under high contact stress in a mild vacuum environment. This noteworthy outcome is primarily attributable to the self-segmentation of the macroscale contact interface during the friction process, involving:(1) a large amount of wear debris is embedded into the wear track to create extensive micro-sized asperities;(2) a nanolayer of amorphous carbon enriched with oxide nanoparticles is formed on the uppermost part of these asperities;(3) numerous incommensurate nanocontacts comprising nanoparticles and highly oriented MoS_(2)nanosheets are established, culminating in the achievement of robust superlubricity. Our pioneering design, coupled with the elucidation of the underlying superlubricity mechanism, holds significant promise for advancing the development of robust and high-performance lubricants.展开更多
基金financially supported by the National Science and Technology Major Project of China for Water Pollution Control and Treatment(No.2013ZX07202-010)。
文摘MnO2-impregnated carbon-coated Fe3 O4(Fe3O4/C/MnO2)nanocomposites with a good core-shell structure were prepared by direct oxidation of carbon-coated Fe3 O4(Fe3O4/C)microspheres with KMnO4 in alkaline solution and applied to adsorb bovine serum albumin(BSA).X-ray diffraction(XRD),transmission electron microscope(TEM),Fourier transform infrared spectrometer(FTIR),vibrating sample magnetometer(VSM)and thermogravimetric analyzer(TGA)tests show that Fe3O4/C microspheres were newly functionalized via the oxidation by KMnO4.Fe3O4/C/MnO2 nanocomposites exhibit a higher adsorption capacity for BSA than Fe3O4/C microspheres and the maximum adsorption of BSA on them occurs at pH 4.7,which is the isoelectric point of BSA.Langmuir isotherm model describes the adsorption of BSA better than Freundlich model and Temkin model,and the kinetics data fit well with the pseudo-second-order model.
基金supported by Key Laboratory of Infrared Imaging Materials and Detectors,Shanghai Institute of Technical Physics,Chinese Academy of Sciences(No.IIMDKFJJ-21-10)China Postdoctoral Science Foundation(No.2018T110993).
文摘In order to achieve combined mechanical and electrical properties,multi-walled carbon nanotubes(MWCNTs)reinforced Cu/Ti_(3)SiC_(2)/C nanocomposites were further processed by high-pressure torsion(HPT).The maximum microhardness values of central and edge from the composites with 1 wt.%MWCNTs reached HV 130.0 and HV 363.5,which were 43.9%and 39.5%higher than those of the original samples,respectively.With the same content of MWCNTs,its electrical conductivity achieved 3.42×10^(7) S/m,which was increased by 78.1%compared with that of original samples.The synergistic improvement of mechanical and electrical properties is attributed to the obtained microstructure with increased homogenization and refinement,as well as improved interfacial bonding and reduced porosity.The strengthening mechanisms include dispersion and refinement strengthening for mechanical properties,as well as reduced electron scattering for electrical properties.
文摘A simple, mild and green approach has been developed for the synthesis of asymmetrical heterobiaryls under the irradiation of visible light without any oxidants and promoting reagents through using Pd/Ce O2 nanocomposite photocatalyst. This method can tolerate considerable functional groups such as electrondonating groups and electron-withdrawing groups through CààC cross-coupling. Moreover, we obtain the products with moderate yields in an efficient way. Finally, a plausible mechanism is proposed.
文摘A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R lines in the fluorescence spectra va ry with the distance from the centre of indentation. The magnitude of load appli ed on the surface of the materials through the indenter influences the shifts of R lines to great extent. The luminescence of R lines of the materials before indenting is used to determine the residual stresses around the indentation in the materials, assuming that the stress tensor is transversely isotropic. Final ly, the term of hydrostatic stress is adopted to explain and compare different residual stresses around indentations with the increase of the indenting load an d the distance from the centre of indentations. <
文摘A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R lines in the fluorescence spectra va ry with the distance from the centre of indentation. The magnitude of load appli ed on the surface of the materials through the indenter influences the shifts of R lines to great extent. The luminescence of R lines of the materials before indenting is used to determine the residual stresses around the indentation in the materials, assuming that the stress tensor is transversely isotropic. Final ly, the term of hydrostatic stress is adopted to explain and compare different residual stresses around indentations with the increase of the indenting load an d the distance from the centre of indentations. 【
基金Islamic Azad University, Gachsaran Branchthe Research Council of Yasouj University for financial support
文摘Tin sulfide nanoparticles(SnS -NPs) were prepared in aqueous solution at room temperature on the surface of activated carbon(AC) and were investigated using field-emission scanning electron mi-croscopy(FE-SEM), transmission electron microscopy(TEM), X-ray diffraction, reflective ultravio-let-visible spectrophotometry, and spectrofluorimetry. Calculations based on the SEM and TEM images showed that the sizes of the SnS -NPs immobilized on the AC were 30–70 nm. The prepared nanocomposite was used as a heterogeneous Lewis acid catalyst for the three-components one-pot synthesis of 4H-pyrano[2,3-c]pyrazole derivatives in ethanol at 80 ℃. The reactions were efficiently performed in the presence of the prepared catalyst in short reaction times, and gave the desired products in high yields. This catalyst can be easily recovered by simple filtration and recycled up to eight consecutive times without significant loss of its efficiency.
文摘为获得一种具有理论容量高、循环性能佳、光催化性能优异的新型多功能材料,在石墨存在下,以钛酸四丁酯为钛源,利用简单的一步溶剂热法制备不同石墨含量的石墨@TiO_(2)复合材料并对其进行表征。将石墨@TiO_(2)复合材料作为锂离子电池负极材料测试了其电化学性能,并将其用作降解甲基橙溶液的光催化剂测试了其光催化性能。结果表明:锐钛矿型TiO_(2)纳米线呈三维相互交织状包覆在石墨片表面,使复合材料具有较高的比表面积;复合材料中TiO_(2)含量越高,其初始放电比容量越大,在100 mA/g电流密度下的初始放电比容量最高可达到464.9 m A·h/g,在2 A/g电流密度下的初始放电比容量最高可达到120.3 mA·h/g;而复合材料中TiO_(2)含量越低,其可逆循环性能越好,在100 m A/g电流密度下循环100次后放电比容量为310.8 mA·h/g;石墨@TiO_(2)复合材料光催化性能随着TiO_(2)含量的增加而增强,在紫外光照射60 min后,甲基橙溶液的降解率最高可达98.72%。研究表明,石墨@TiO_(2)复合材料具有优异的电化学性能和光催化性能,有望替代传统的负极材料和光催化剂材料,具有广阔的应用前景。
基金the Major Projects of Science and Technology in Tianjin(No.18ZXJMTG00020).
文摘Triboelectric nanogenerator(TENG)can realize a variety of mechanical energy collections in the environment,which has great potential in the field of wearable energy.However,many TENGs could rarely be satisfactory to wearable electronics promotion because of their expensive raw materials and complex manufacturing processes.In this study,a type of porous structure carbon powder/manganese dioxide(C/MnO_(2))nanocomposite is introduced.The material adopts low-cost,high-yield carbon powder,can be prepared in one step through a simple,economical,and environmentally friendly hydrothermal preparation process,and has high economic practicality.Superior power generation performance was obtained by modulating the charge trapping ability and storage capacity of polydimethylsiloxane@C/MnO_(2)(PDMS@C/MnO_(2))film based on variations in the weight-loading of C/MnO_(2).The maximum output voltage of carbon powder/manganese dioxide TENG(CM-TENG)is 63 V,which is 2.1 times that of PDMS-TENG and 1.86 times that of carbon powder TENG(C-TENG)and can easily light up 53 LEDs.Furthermore,CM-TENG can convert biological motion energy into electrical signals to detect human hand movements.The CM-TENG self-powered system can successfully drive various microelectronic devices,such as electronic watches,liquid crystal displays(LCDs),and calculators.This study provides a reliable,low-cost,high-performance,and widely applicable electronic system that shows great potential in future fields such as wearable devices and micro-sensing systems.
基金supported by the PhD Start-up Fund of Science and Technology Department of Liaoning Province(No.2022-BS-306)the General Cultivation Scientific Research Project of Bohai University(No.0522xn058)the PhD Research Startup Foundation of Bohai University(No.0521bs021).
文摘The key to solve increasingly severe electromagnetic(EM)pollution is to explore sustainable,easily prepared,and cost-effective EM wave absorption materials with exceptional absorption capability.Herein,instead of anchoring on carbon materials in single layer,MoS_(2) flower-like microspheres were stacked on the surface of pomelo peels-derived porous carbon nanosheets(C)to fabricate MoS_(2)@C nanocomposites by a facile solvothermal process.EM wave absorption performances of MoS_(2)@C nanocomposites in X-band were systematically investigated,indicating the minimum reflection loss(RLmin)of-62.3 dB(thickness of 2.88 mm)and effective absorption bandwidth(EAB)almost covering the whole X-band(thickness of 2.63 mm)with the filler loading of only 20 wt.%.Superior EM wave absorption performances of MoS_(2)@C nanocomposites could be attributed to the excellent impedance matching characteristic and dielectric loss capacity(conduction loss and polarization loss).This study revealed that the as-prepared MoS_(2)@C nanocomposites would be a novel prospective candidate for the sustainable EM absorbents with superior EM wave absorption performances.
基金supported by the National Natural Science Foundation of China (Grant Nos. U21A20127, 52375220)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB 0470302)the Natural Science Foundation of Ningbo (Grant No. 2022J300)。
文摘Molybdenum disulfide(MoS_(2)) films are widely deployed in industrial applications owing to their inherent interlayer slip characteristics, offering energy consumption savings and prolonged mechanical part performance. Nevertheless, their practical utility is limited by environmental constraints and the limitations of preparation techniques, which hinder the attainment of robust superlubricity(friction coefficient < 0.01). Herein, through magnetron sputtering technology, we synthesize a core-shell-like nanocomposite composed of MoS_(2)nanosheets encapsulating B_(4)C. The core-shell-like structure enables the resulting films to preferentially grow crystalline MoS_(2), providing them with outstanding mechanical properties and efficient lubrication over a wide range of temperatures. Remarkably, such film achieves robust macroscale superlubricity and an ultralow wear rate(1.7 ×10^(-8)mm^(3)N-1m^(-1)) under high contact stress in a mild vacuum environment. This noteworthy outcome is primarily attributable to the self-segmentation of the macroscale contact interface during the friction process, involving:(1) a large amount of wear debris is embedded into the wear track to create extensive micro-sized asperities;(2) a nanolayer of amorphous carbon enriched with oxide nanoparticles is formed on the uppermost part of these asperities;(3) numerous incommensurate nanocontacts comprising nanoparticles and highly oriented MoS_(2)nanosheets are established, culminating in the achievement of robust superlubricity. Our pioneering design, coupled with the elucidation of the underlying superlubricity mechanism, holds significant promise for advancing the development of robust and high-performance lubricants.
