Herein,phosphorus-mediated sulfur nanoparticles encapsulated in reduced graphene oxide nanosheets(P-SrGO-T)were successfully synthesized as the cathode for sodium ion battery by a ball milling and the following therma...Herein,phosphorus-mediated sulfur nanoparticles encapsulated in reduced graphene oxide nanosheets(P-SrGO-T)were successfully synthesized as the cathode for sodium ion battery by a ball milling and the following thermal treatment.A series of covalent bonds,such as P–S,C–S–C,C–O–P and C–S–P,are formed in this process,which are in favor of fixing the sulfur and suppressing the parasitic shuttle effect of polysulfide.Benefiting from the graphene sheets and these covalent bonds,a high reversible capacity of 637.4 m Ah/g was achieved in P-SrGO-T after 100 cycles at the current density of 0.2 A/g.In addition,P-SrGO-T also delivers a high-rate capacity(330.7 m Ah/g at 5 A/g)attributing to low charge transfer resistance and faster ion diffusion kinetic.This work pushes the progress forward in developing phosphosulfide cathode for sodium ion batteries.展开更多
Microstructural evolution and strengthening mechanisms of Mg-3Sn-1Ca based alloys with additions of different amounts of Al N nanoparticles were investigated.It was found that with increasing the amount of AlN nano-pa...Microstructural evolution and strengthening mechanisms of Mg-3Sn-1Ca based alloys with additions of different amounts of Al N nanoparticles were investigated.It was found that with increasing the amount of AlN nano-particles the grain size decreases obviously.The existence of AlN nano-particles could refine the primary crystal phases CaMgSn,which provided more heterogeneous nucleation sites for the formation of magnesium.Moreover,such nano-particles could also restrict the grain growth during solidification.After adding AlN nano-particles,both the tensile properties at room temperature and high temperature 250℃and the hardness are largely improved.The improvement of strength is attributed to grain refinement and second phase refinement.展开更多
Highly active transition metal nitrides are desirable for electrocatalytic reactions,but their long-term stability is still unsatisfactory and thus limiting commercial applications.Herein,for the first time,we report ...Highly active transition metal nitrides are desirable for electrocatalytic reactions,but their long-term stability is still unsatisfactory and thus limiting commercial applications.Herein,for the first time,we report a unique and universal room-temperature urea plasma method for controllable synthesis of N-doped carbon coated metal(Fe,Co,Ni,etc.)nitrides arrays electrocatalysts.The preformed metal oxides arrays can be successfully converted into metal nitrides arrays with preserved nanostructures and a thin layer of N-doped carbon(N-C)via one-step urea plasma.Typically,as a representative case,N-C@CoN nanowire arrays are illustrated and corresponding formation mechanism by plasma is proposed.Notably,the designed N-C@Co N catalysts deliver excellent electrocatalytic activity and long-term stability both in oxygen evolution reaction(OER)and urea oxidation reaction(UOR).For OER,a low overpotential(264 mV at 10 mA/cm^(2))and high stability(>50 h at 20 mA/cm^(2))are acquired.For UOR,a current density of100 m A/cm^(2) is achieved at only 1.39 V and maintain over 100 h.Theoretical calculations reveal that the synergetic coupling effect of CoN and N-C can significantly facilitate the charge-transfer process,optimize adsorbed intermediates binding strength and further greatly decrease the energy barrier.This strategy provides a novel method for fabrication of N-C@metal nitrides as highly active and stable catalysts.展开更多
基金sponsored by National Natural Science Foundation of China(Nos.21701017,52002052)。
文摘Herein,phosphorus-mediated sulfur nanoparticles encapsulated in reduced graphene oxide nanosheets(P-SrGO-T)were successfully synthesized as the cathode for sodium ion battery by a ball milling and the following thermal treatment.A series of covalent bonds,such as P–S,C–S–C,C–O–P and C–S–P,are formed in this process,which are in favor of fixing the sulfur and suppressing the parasitic shuttle effect of polysulfide.Benefiting from the graphene sheets and these covalent bonds,a high reversible capacity of 637.4 m Ah/g was achieved in P-SrGO-T after 100 cycles at the current density of 0.2 A/g.In addition,P-SrGO-T also delivers a high-rate capacity(330.7 m Ah/g at 5 A/g)attributing to low charge transfer resistance and faster ion diffusion kinetic.This work pushes the progress forward in developing phosphosulfide cathode for sodium ion batteries.
基金financially supported by the Study Abroad Program by the Government of Shandong Province(201802005)Linyi Industrial Technology Research Institute and Shandong Yinguang Yuyuan Light Metal Precise Forming Co.,Ltd。
文摘Microstructural evolution and strengthening mechanisms of Mg-3Sn-1Ca based alloys with additions of different amounts of Al N nanoparticles were investigated.It was found that with increasing the amount of AlN nano-particles the grain size decreases obviously.The existence of AlN nano-particles could refine the primary crystal phases CaMgSn,which provided more heterogeneous nucleation sites for the formation of magnesium.Moreover,such nano-particles could also restrict the grain growth during solidification.After adding AlN nano-particles,both the tensile properties at room temperature and high temperature 250℃and the hardness are largely improved.The improvement of strength is attributed to grain refinement and second phase refinement.
基金supported by National Natural Science Foundation of China(No.52073252)Science and Technology Department of Zhejiang Province(No.2023C01231)+2 种基金Key Research and Development Project of Science and Technology Department of Sichuan Province(No.2022YFSY0004)Key Laboratory of Engineering Dielectrics and Its Application(Harbin University of Science and Technology)Ministry of Education(No.KFM 202202),and the Open Project Program of the State Key Laboratory of New textile Materials and Advanced Processing Technologies(No.FZ2021009)。
文摘Highly active transition metal nitrides are desirable for electrocatalytic reactions,but their long-term stability is still unsatisfactory and thus limiting commercial applications.Herein,for the first time,we report a unique and universal room-temperature urea plasma method for controllable synthesis of N-doped carbon coated metal(Fe,Co,Ni,etc.)nitrides arrays electrocatalysts.The preformed metal oxides arrays can be successfully converted into metal nitrides arrays with preserved nanostructures and a thin layer of N-doped carbon(N-C)via one-step urea plasma.Typically,as a representative case,N-C@CoN nanowire arrays are illustrated and corresponding formation mechanism by plasma is proposed.Notably,the designed N-C@Co N catalysts deliver excellent electrocatalytic activity and long-term stability both in oxygen evolution reaction(OER)and urea oxidation reaction(UOR).For OER,a low overpotential(264 mV at 10 mA/cm^(2))and high stability(>50 h at 20 mA/cm^(2))are acquired.For UOR,a current density of100 m A/cm^(2) is achieved at only 1.39 V and maintain over 100 h.Theoretical calculations reveal that the synergetic coupling effect of CoN and N-C can significantly facilitate the charge-transfer process,optimize adsorbed intermediates binding strength and further greatly decrease the energy barrier.This strategy provides a novel method for fabrication of N-C@metal nitrides as highly active and stable catalysts.
