Rechargeable magnesium batteries(RMBs),as one of the most promising candidates for efficient energy storage devices with high energy,power density and high safety,have attracted increasing attention.However,searching ...Rechargeable magnesium batteries(RMBs),as one of the most promising candidates for efficient energy storage devices with high energy,power density and high safety,have attracted increasing attention.However,searching for suitable cathode materials with fast diffusion kinetics and exploring their magnesium storage mechanisms remains a great challenge.Cu S submicron spheres,made by a facile low-temperature synthesis strategy,were applied as the high-performance cathode for RMBs in this work,which can deliver a high specific capacity of 396mAh g^(-1)at 20 mA g^(-1) and a remarkable rate capacity of 250 m Ah g^(-1)at 1000 mA g^(-1).The excellent rate performance can be assigned to the nano needle-like particles on the surface of Cu S submicron spheres,which can facilitate the diffusion kinetics of Mg^(2+).Further storage mechanism investigations illustrate that the Cu S cathodes experience a two-step conversion reaction controlled by diffusion during the electrochemical reaction process.This work could make a contribution to the study of the enhancement of diffusion kinetics of Mg2+and the reaction mechanism of RMBs.展开更多
To inhibit the agglomeration of tin-based nanomaterials and simplify the complicated synthesis process,a facile and eco-friendly self-formed template method is reported to synthesize tin submicron spheres dispersed in...To inhibit the agglomeration of tin-based nanomaterials and simplify the complicated synthesis process,a facile and eco-friendly self-formed template method is reported to synthesize tin submicron spheres dispersed in nitrogen-doped porous carbon(Sn/NPC)by pyrolysis of a mixture of disodium stannous citrate and urea.The vital point of this strategy is the formation of Na_(2)CO_(3)templates during pyrolysis.This self-formed Na_(2)CO_(3)acts as porous templates to support the formation of NPC.The obtained NPC provides good electronic conductivity,ample defects,and more active sites.Serving as anode for Li-ion batteries,the Sn/NPC electrode obtains a stable discharge capacity of 674.1 mAh/g after 150 cycles at 0.1 A/g.Especially,a high discharge capacity of 331.2 mAh/g can be achieved after 1100 cycles at 3 A/g.Additionally,a full cell coupled with LiCoO_(2)as cathode yields a discharge capacity of 524.8 mAh/g after 150 cycles at 0.1 A/g.In-situ XRD is implemented to investigate the alloying/dealloying reaction mechanisms.Density functional theory calculation ulteriorly explicates that NPC heightens intrinsic electronic conductivity,and NPC especially pyrrolic-N and pyridinic-N doping facilitates the Li-adsorption ability.Climbing image nudged elastic band method reveals low Li~+diffusion energy barrier in presence of N atoms,which accounts for the terrific electrochemical properties of Sn/NPC electrode.展开更多
Lignin serves as a promising Ultraviolet(UV)absorber within sunscreen industry.However,the commercial development of lignin-containing sunscreens faces challenges due to their low sun protection factor(SPF)and dark co...Lignin serves as a promising Ultraviolet(UV)absorber within sunscreen industry.However,the commercial development of lignin-containing sunscreens faces challenges due to their low sun protection factor(SPF)and dark color in cosmetics industry.In this study,dual modifications on the chemical and physical structures of lignin were conducted to address these challenges.Initially,methylene bis-benzotriazolyl tetramethylbutylphenol(MBBT)was grafted onto alkali lignin(AL)through an atom transfer radical polymerization reaction,resulting in a polymer of AL-graft-MBBT_(3)(AL-g-MBBT_(3)).The sunscreen prepared with 10%AL-g-MBBT_(3) displays outstand-ing sun protection performance with a SPF of 42.93 and a light color with a color difference value(ΔE)of 45.6,in contrast to 10%AL with a SPF of 4.74 and aΔE value of 49.5.Subsequently,AL-g-MBBT_(3) was transformed into normal submicron spheres(AL-g-MBBT_(3) N)and TiO_(2)-loading submicron spheres(AL-g-MBBT_(3)/TiO_(2)).The sun protection performances of 10%AL-g-MBBT_(3) N@C and AL-g-MBBT_(3)/TiO_(2)@C sunscreens obviously surpass that of AL-g-MBBT_(3)@C sunscreen,achieving SPFs of 60.38 and 66.20,respectively.Additionally,there is a considerable improve-ment in the color of these sunscreens,withΔE values of 41.8 and 36.3,respectively.These results provide valuable insights into exploring lignin’s high-value applications in sunscreen.展开更多
基金the support from the Fundamental Research Funds for the Central Universities of Chongqing University(No.2020CDCGCL005)。
文摘Rechargeable magnesium batteries(RMBs),as one of the most promising candidates for efficient energy storage devices with high energy,power density and high safety,have attracted increasing attention.However,searching for suitable cathode materials with fast diffusion kinetics and exploring their magnesium storage mechanisms remains a great challenge.Cu S submicron spheres,made by a facile low-temperature synthesis strategy,were applied as the high-performance cathode for RMBs in this work,which can deliver a high specific capacity of 396mAh g^(-1)at 20 mA g^(-1) and a remarkable rate capacity of 250 m Ah g^(-1)at 1000 mA g^(-1).The excellent rate performance can be assigned to the nano needle-like particles on the surface of Cu S submicron spheres,which can facilitate the diffusion kinetics of Mg^(2+).Further storage mechanism investigations illustrate that the Cu S cathodes experience a two-step conversion reaction controlled by diffusion during the electrochemical reaction process.This work could make a contribution to the study of the enhancement of diffusion kinetics of Mg2+and the reaction mechanism of RMBs.
基金supported by the China Postdoctoral Science Foundation(No.2020M670719)the Doctoral Research Startup Fund of Liaoning Province(No.2020-BS-066)the Fundamental Research Funds for the Central Universities(No.3132019328)。
文摘To inhibit the agglomeration of tin-based nanomaterials and simplify the complicated synthesis process,a facile and eco-friendly self-formed template method is reported to synthesize tin submicron spheres dispersed in nitrogen-doped porous carbon(Sn/NPC)by pyrolysis of a mixture of disodium stannous citrate and urea.The vital point of this strategy is the formation of Na_(2)CO_(3)templates during pyrolysis.This self-formed Na_(2)CO_(3)acts as porous templates to support the formation of NPC.The obtained NPC provides good electronic conductivity,ample defects,and more active sites.Serving as anode for Li-ion batteries,the Sn/NPC electrode obtains a stable discharge capacity of 674.1 mAh/g after 150 cycles at 0.1 A/g.Especially,a high discharge capacity of 331.2 mAh/g can be achieved after 1100 cycles at 3 A/g.Additionally,a full cell coupled with LiCoO_(2)as cathode yields a discharge capacity of 524.8 mAh/g after 150 cycles at 0.1 A/g.In-situ XRD is implemented to investigate the alloying/dealloying reaction mechanisms.Density functional theory calculation ulteriorly explicates that NPC heightens intrinsic electronic conductivity,and NPC especially pyrrolic-N and pyridinic-N doping facilitates the Li-adsorption ability.Climbing image nudged elastic band method reveals low Li~+diffusion energy barrier in presence of N atoms,which accounts for the terrific electrochemical properties of Sn/NPC electrode.
基金support for this work by Natural Science Foundation of Guangxi Province,China(No.2021GXNSFDA196006)National Natural Science Foundation of China(No.22268007+1 种基金No.21766002)Guangxi Innovation Driven Development Special Fund Project,China(No.AA17204092).
文摘Lignin serves as a promising Ultraviolet(UV)absorber within sunscreen industry.However,the commercial development of lignin-containing sunscreens faces challenges due to their low sun protection factor(SPF)and dark color in cosmetics industry.In this study,dual modifications on the chemical and physical structures of lignin were conducted to address these challenges.Initially,methylene bis-benzotriazolyl tetramethylbutylphenol(MBBT)was grafted onto alkali lignin(AL)through an atom transfer radical polymerization reaction,resulting in a polymer of AL-graft-MBBT_(3)(AL-g-MBBT_(3)).The sunscreen prepared with 10%AL-g-MBBT_(3) displays outstand-ing sun protection performance with a SPF of 42.93 and a light color with a color difference value(ΔE)of 45.6,in contrast to 10%AL with a SPF of 4.74 and aΔE value of 49.5.Subsequently,AL-g-MBBT_(3) was transformed into normal submicron spheres(AL-g-MBBT_(3) N)and TiO_(2)-loading submicron spheres(AL-g-MBBT_(3)/TiO_(2)).The sun protection performances of 10%AL-g-MBBT_(3) N@C and AL-g-MBBT_(3)/TiO_(2)@C sunscreens obviously surpass that of AL-g-MBBT_(3)@C sunscreen,achieving SPFs of 60.38 and 66.20,respectively.Additionally,there is a considerable improve-ment in the color of these sunscreens,withΔE values of 41.8 and 36.3,respectively.These results provide valuable insights into exploring lignin’s high-value applications in sunscreen.
