Ti_(3)AlC_(2)-reinforced Ag-based composites,which are used as sliding current collectors,electrical contacts,and electrode materials,exhibit remarkable performances.However,the interfacial reactions between Ag and Ti...Ti_(3)AlC_(2)-reinforced Ag-based composites,which are used as sliding current collectors,electrical contacts,and electrode materials,exhibit remarkable performances.However,the interfacial reactions between Ag and Ti_(3)AlC_(2) significantly degrade the electrical and thermal properties of these composites.To diminish these interfacial reactions,we fabricated carbon-coated Ti_(3)AlC_(2) particles(C@Ti_(3)AlC_(2))as reinforcement and prepared Ag–10wt%C@Ti_(3)AlC_(2) composites with carbon-layer thicknesses ranging from 50–200 nm.Compared with the uncoated Ag–Ti_(3)AlC_(2) composite,Ag–C@Ti_(3)AlC_(2) was found to have a better distribution of Ti_(3)AlC_(2) particles.With increases in the carbon-layer thickness,the Vickers hardness value and relative density of Ag–C@Ti_(3)AlC_(2) gradually decreases.With a carbon-layer thickness of 150 nm,we obtained the lowest resistivity of Ag–C@Ti_(3)AlC_(2) of 29.4135.5×10^(−9)Ω·m,which is half that of Ag–Ti_(3)AlC_(2)(66.7×10^(−9)Ω·m).The thermal conductivity of Ag–C@Ti_(3)AlC_(2) reached a maximum value of 135.5 W·m^(−1)·K^(−1) with a 200-nm carbon coating(~1.8 times that of Ag–Ti_(3)AlC_(2)).These results indicate that the carbon-coating method is a feasible strategy for improving the performance of Ag–C@Ti_(3)AlC_(2) composites.展开更多
Titania nanowires(TiO2-NW)with tunable aspect ratios and morphologies were directly synthesized using a simple alcohol-thermal technique.Specifically,ethanol and acetic acid were used as solvents and lithium ion was u...Titania nanowires(TiO2-NW)with tunable aspect ratios and morphologies were directly synthesized using a simple alcohol-thermal technique.Specifically,ethanol and acetic acid were used as solvents and lithium ion was used as the capping agent to promote the conversion of titanium butoxide into TiO2-NW.The morphologies and crystal phases of TiO2-NW were determined by the molar ratio of solvents and the content(mol%)of lithium ion.The band gap of TiO2-NW with pure anatase phase is slightly bigger than that of TiO2-NW with a mixture of anatase and rutile phases.All TiO2-NW could achieve effective decolorization of methyl blue(the decolorization rate is over 95%)after 35-min ultraviolet(UV)irradiation.展开更多
Burning of fuels is an irreversible entropy increasing process,requiring additional energies derived from the environment to let the process cycle.In theory,photon energy delivered from the sun could fix the huge ener...Burning of fuels is an irreversible entropy increasing process,requiring additional energies derived from the environment to let the process cycle.In theory,photon energy delivered from the sun could fix the huge energy demand in a clean and sustainable way.Photocatalysis is such an ideal approach to reconvert inert molecules directly into fuels and other chemical feedstocks using photon energy without any other energy inputs.展开更多
基金supported by the National Natural Science Foundation of China(No.21773297,No.21973108,and No.21921004)supported by the National Natural Science Foundation of China(No.21805258)supported by the National Natural Science Foundation of China(No.21973107)。
基金financial support of the National Natural Science Foundation of China(Nos.51731004 and 51671054)the Natural Science Foundation of Jiangsu Province(No.BK20181285)the Fundamental Research Funds for the Central Universities,China(No.2242019K 40056).
文摘Ti_(3)AlC_(2)-reinforced Ag-based composites,which are used as sliding current collectors,electrical contacts,and electrode materials,exhibit remarkable performances.However,the interfacial reactions between Ag and Ti_(3)AlC_(2) significantly degrade the electrical and thermal properties of these composites.To diminish these interfacial reactions,we fabricated carbon-coated Ti_(3)AlC_(2) particles(C@Ti_(3)AlC_(2))as reinforcement and prepared Ag–10wt%C@Ti_(3)AlC_(2) composites with carbon-layer thicknesses ranging from 50–200 nm.Compared with the uncoated Ag–Ti_(3)AlC_(2) composite,Ag–C@Ti_(3)AlC_(2) was found to have a better distribution of Ti_(3)AlC_(2) particles.With increases in the carbon-layer thickness,the Vickers hardness value and relative density of Ag–C@Ti_(3)AlC_(2) gradually decreases.With a carbon-layer thickness of 150 nm,we obtained the lowest resistivity of Ag–C@Ti_(3)AlC_(2) of 29.4135.5×10^(−9)Ω·m,which is half that of Ag–Ti_(3)AlC_(2)(66.7×10^(−9)Ω·m).The thermal conductivity of Ag–C@Ti_(3)AlC_(2) reached a maximum value of 135.5 W·m^(−1)·K^(−1) with a 200-nm carbon coating(~1.8 times that of Ag–Ti_(3)AlC_(2)).These results indicate that the carbon-coating method is a feasible strategy for improving the performance of Ag–C@Ti_(3)AlC_(2) composites.
基金financially supported by the National Natural Science Foundation of China (No. 51408528)the Natural Science Foundation of Hebei Province, China (No. E2014203089)
文摘Titania nanowires(TiO2-NW)with tunable aspect ratios and morphologies were directly synthesized using a simple alcohol-thermal technique.Specifically,ethanol and acetic acid were used as solvents and lithium ion was used as the capping agent to promote the conversion of titanium butoxide into TiO2-NW.The morphologies and crystal phases of TiO2-NW were determined by the molar ratio of solvents and the content(mol%)of lithium ion.The band gap of TiO2-NW with pure anatase phase is slightly bigger than that of TiO2-NW with a mixture of anatase and rutile phases.All TiO2-NW could achieve effective decolorization of methyl blue(the decolorization rate is over 95%)after 35-min ultraviolet(UV)irradiation.
文摘Burning of fuels is an irreversible entropy increasing process,requiring additional energies derived from the environment to let the process cycle.In theory,photon energy delivered from the sun could fix the huge energy demand in a clean and sustainable way.Photocatalysis is such an ideal approach to reconvert inert molecules directly into fuels and other chemical feedstocks using photon energy without any other energy inputs.
