Li metal anode holds great promise to realize high-energy battery systems.However,the safety issue and limited lifetime caused by the uncontrollable growth of Li dendrites hinder its commercial application.Herein,an i...Li metal anode holds great promise to realize high-energy battery systems.However,the safety issue and limited lifetime caused by the uncontrollable growth of Li dendrites hinder its commercial application.Herein,an interlayer-bridged 3D lithiophilic rGO-Ag-S-CNT composite is proposed to guide uniform and stable Li plating/stripping.The 3D lithiophilic rGO-Ag-S-CNT host is fabricated by incorporating Ag-modified reduced graphene oxide(rGO)with S-doped carbon nanotube(CNT),where the rGO and CNT are closely connected via robust Ag-S covalent bond.This strong Ag-S bond could enhance the structural stability and electrical connection between rGO and CNT,significantly improving the electrochemical kinetics and uniformity of current distribution.Moreover,density functional theory calculation indicates that the introduction of Ag-S bond could further boost the binding energy between Ag and Li,which promotes homogeneous Li nucleation and growth.Consequently,the rGO-Ag-S-CNT-based anode achieves a lower overpotential(7.3 mV at 0.5 mA cm^(−2)),higher Coulombic efficiency(98.1%at 0.5 mA cm^(−2)),and superior long cycling performance(over 500 cycles at 2 mA cm−2)as compared with the rGO-Ag-CNT-and rGO-CNT-based anodes.This work provides a universal avenue and guidance to build a robust Li metal host via constructing a strong covalent bond,effectively suppressing the Li dendrites growth to prompt the development of Li metal battery.展开更多
High-performance composites containing various kinds of nanofibers as reinforcing building blocks have recently received considerable attention, owing to their superior mechanical properties. One of the effective stra...High-performance composites containing various kinds of nanofibers as reinforcing building blocks have recently received considerable attention, owing to their superior mechanical properties. One of the effective strategies to reinforce these composites involves strengthening interfacial interactions via covalent bonds. However, in contrast to nanosheets, covalent bonds have been rarely used in nanofiber-reinforced composites. Herein, we report the macroscale fabrication of a series of Ag nanowire （NW）-thiolated chitosan （TCS） composite films via spray induced self-assembly. The obtained films were significantly strengthened by Ag-S covalent bonds formed between the Ag NWs and the thiol groups of TCS. The tensile strength of the optimized Ag NW-TCS film was up to 3.9 and 1.5 times higher compared with that of pure TCS and Ag NW-chitosan （CS） films, respectively.展开更多
Zinc(Zn)alloys exhibit substantial potential for application in the domain of metal materials that are both biodegradable and implantable because of their appropriate degradation rate and biocompatibility.Selenium(Se)...Zinc(Zn)alloys exhibit substantial potential for application in the domain of metal materials that are both biodegradable and implantable because of their appropriate degradation rate and biocompatibility.Selenium(Se)has been widely employed in tumor treatment,positioning ZnSe alloys as promising candidates for the development of the next generation of antitumor degradable materials.However,the considerable disparity in melting points and the volatility of elemental Zn and Se pose significant challenges for alloying using conventional melting methods.Here,we report a Zn-4Ag-2Se alloy using silver selenide(Ag2Se)as the Se source for biodegradable implant materials.The alloy's antibacterial and antitumor capabilities,along with its mechanical,corrosion,and biocompatibility properties,were assessed and then compared to the properties of a Zn-4Ag alloy.Both alloys consisted primarily ofη-Zn andε-AgZn3phases,with the Zn-4Ag-2Se alloy additionally containing a minor amount of a ZnSe phase.The hot-rolled(HR)Zn-4Ag-2Se alloy exhibited an ultimate tensile strength of 211.5±2.3 MPa and elongation of 24.9%±0.6%.Additionally,the HR Zn-4Ag-2Se alloy demonstrated an electrochemical corrosion rate of 105.51±1.21μm year^(-1)and degradation rate of 59.8±0.2μm year^(-1)in Hanks'solution,meeting the performance criteria for degradable implant materials.The HR Zn-4Ag-2Se alloy also exhibited excellent antibacterial activity,evidenced by an inhibition zone diameter(IZD)of 2.22±0.01 mm and colony-forming unit count of 58±2.The HR Zn-4Ag-2Se alloy did not inhibit the proliferation of MC3T3-E1 cells but promoted reactive oxygen species production and finally cell death toward MG63 osteosarcoma cells.展开更多
基金This work is supported by Singapore Ministry of Education academic research grant Tier 2 (MOE2019-T2-1-181).
文摘Li metal anode holds great promise to realize high-energy battery systems.However,the safety issue and limited lifetime caused by the uncontrollable growth of Li dendrites hinder its commercial application.Herein,an interlayer-bridged 3D lithiophilic rGO-Ag-S-CNT composite is proposed to guide uniform and stable Li plating/stripping.The 3D lithiophilic rGO-Ag-S-CNT host is fabricated by incorporating Ag-modified reduced graphene oxide(rGO)with S-doped carbon nanotube(CNT),where the rGO and CNT are closely connected via robust Ag-S covalent bond.This strong Ag-S bond could enhance the structural stability and electrical connection between rGO and CNT,significantly improving the electrochemical kinetics and uniformity of current distribution.Moreover,density functional theory calculation indicates that the introduction of Ag-S bond could further boost the binding energy between Ag and Li,which promotes homogeneous Li nucleation and growth.Consequently,the rGO-Ag-S-CNT-based anode achieves a lower overpotential(7.3 mV at 0.5 mA cm^(−2)),higher Coulombic efficiency(98.1%at 0.5 mA cm^(−2)),and superior long cycling performance(over 500 cycles at 2 mA cm−2)as compared with the rGO-Ag-CNT-and rGO-CNT-based anodes.This work provides a universal avenue and guidance to build a robust Li metal host via constructing a strong covalent bond,effectively suppressing the Li dendrites growth to prompt the development of Li metal battery.
文摘High-performance composites containing various kinds of nanofibers as reinforcing building blocks have recently received considerable attention, owing to their superior mechanical properties. One of the effective strategies to reinforce these composites involves strengthening interfacial interactions via covalent bonds. However, in contrast to nanosheets, covalent bonds have been rarely used in nanofiber-reinforced composites. Herein, we report the macroscale fabrication of a series of Ag nanowire （NW）-thiolated chitosan （TCS） composite films via spray induced self-assembly. The obtained films were significantly strengthened by Ag-S covalent bonds formed between the Ag NWs and the thiol groups of TCS. The tensile strength of the optimized Ag NW-TCS film was up to 3.9 and 1.5 times higher compared with that of pure TCS and Ag NW-chitosan （CS） films, respectively.
基金financially supported by the National Natural Science Foundation of China(Nos.52401064 and 12472101)the Scientific Research Fund of Hunan Provincial Education Department(No.24B0172)+1 种基金Australian Research Council(ARC)through the discovery grants(No.DP240101131)the Post-graduate Scientific Research Innovation Project of Hunan Province(No.CX20230657)
文摘Zinc(Zn)alloys exhibit substantial potential for application in the domain of metal materials that are both biodegradable and implantable because of their appropriate degradation rate and biocompatibility.Selenium(Se)has been widely employed in tumor treatment,positioning ZnSe alloys as promising candidates for the development of the next generation of antitumor degradable materials.However,the considerable disparity in melting points and the volatility of elemental Zn and Se pose significant challenges for alloying using conventional melting methods.Here,we report a Zn-4Ag-2Se alloy using silver selenide(Ag2Se)as the Se source for biodegradable implant materials.The alloy's antibacterial and antitumor capabilities,along with its mechanical,corrosion,and biocompatibility properties,were assessed and then compared to the properties of a Zn-4Ag alloy.Both alloys consisted primarily ofη-Zn andε-AgZn3phases,with the Zn-4Ag-2Se alloy additionally containing a minor amount of a ZnSe phase.The hot-rolled(HR)Zn-4Ag-2Se alloy exhibited an ultimate tensile strength of 211.5±2.3 MPa and elongation of 24.9%±0.6%.Additionally,the HR Zn-4Ag-2Se alloy demonstrated an electrochemical corrosion rate of 105.51±1.21μm year^(-1)and degradation rate of 59.8±0.2μm year^(-1)in Hanks'solution,meeting the performance criteria for degradable implant materials.The HR Zn-4Ag-2Se alloy also exhibited excellent antibacterial activity,evidenced by an inhibition zone diameter(IZD)of 2.22±0.01 mm and colony-forming unit count of 58±2.The HR Zn-4Ag-2Se alloy did not inhibit the proliferation of MC3T3-E1 cells but promoted reactive oxygen species production and finally cell death toward MG63 osteosarcoma cells.
