Transition metal dichalcogenides are attractive anode materials for sodium ion batteries(SIBs)due to their high theoretical capacity and large interlayer spacing.However,its practical application is hampered by the sl...Transition metal dichalcogenides are attractive anode materials for sodium ion batteries(SIBs)due to their high theoretical capacity and large interlayer spacing.However,its practical application is hampered by the sluggish kinetics of Na^(+)insertion and structure collapse caused by Na^(+)insertion/deinsertion.Herein,the heterostructures of MoSe_(2) nanosheets vertically growing on bowl-like carbon(MoSe_(2)@C)are designed and prepared by a template method coupled with selenization treatment to boost storage sodium performance.The hollow and collapse could provide enough storage space for Na^(+)and alleviate the volume expansion during the charge/discharge processes.MoSe_(2) nanosheets vertically grown on carbon could expose more active sites for adsorbing Na^(+)to enhance the utilization rate of electrode materials.Moreover,building heterostructures by combining different phase components could facilitate Na^(+)diffusion and advance reaction kinetics.Benefiting from these merits,the bowl-like MoSe_(2)@C shows outstanding reversible capacity(356.8 mAh·g^(-1) after 1500 cycles at 1 A·g^(-1))and remarkable rate performance(249.9 mAh·g^(-1)10 A·g^(-1)).展开更多
NH_(3) plays an essential role in human life since it is an important raw material for fertilizers,plastics and rubbers production.As an NH_(3) synthesis technology under ambient conditions,electrocatalytic N_(2) redu...NH_(3) plays an essential role in human life since it is an important raw material for fertilizers,plastics and rubbers production.As an NH_(3) synthesis technology under ambient conditions,electrocatalytic N_(2) reduction reaction(NRR)has great potential to replace the energy-intensive Haber-Bosch process.The key of electrocatalytic NRR is the exploration of efficient catalysts.Transition metal Mo is promising since it exists naturally in nitrogenase due to the unique Mo-N_(2) interaction;particularly in the form of 2D material such as MoSe_(2),the surface area is maximized for more active sites.However,the NRR performance of MoSe_(2) is still unsatisfactory because Mo is only exposed at the semi-open edge,and the electronegative Se-mantled surface area remains inaccessible to N_(2).Herein,we propose a simple and effective strategy to create high-concentration Se vacancies in MoSe_(2) through heteroatom doping induced lattice strain,which effectively enhances the Mo-N_(2) interaction on the surface area.In result,high NH_(3) yield(3.04×10^(–10)mol s^(–1)cm^(–2))and Faraday efficiency(21.61%)are attained at–0.45 V vs.RHE in 0.1 mol/L Na_(2)SO_(4).展开更多
Transition metal nitrides have become the focus of research in sodium ion batteries(SIBs)due to their unique metal properties and high theoretical capacity.However,the low actual capacity is still the main bottleneck ...Transition metal nitrides have become the focus of research in sodium ion batteries(SIBs)due to their unique metal properties and high theoretical capacity.However,the low actual capacity is still the main bottleneck for their application.Herein,using Mo-aniline frameworks as precursors,the carbon encapsulated nitrogen-rich Mo_(x)N is decorated by few-layered MoSe_(2) nanosheets(MoSe_(2)@Mo_(x)N/C-I)after the facile calcinating,selenizing,and nitriding.The carbon encapsulation can effectively strengthen the structural stability of Mo_(x)N.The nitrogen-rich Mo_(x)N and decoration of few-layered MoSe_(2) can create rich heterointerfaces and extra active sites for rapid sodium-ion storage,thus promoting reaction kinetics and improving actual capacity.The MoSe_(2)@Mo_(x)N/C-I as an anode achieves a large reversible capacity of 522.8 mAh g^(-1)at 0.1 A g^(-1),and 254.3 mAh g^(-1)capacity is obtained after 6000 cycles at 5.0 A g^(-1),showing signally improved sodium-ion storage properties.The storage mechanisms and kinetic behaviors are described systematically via the advanced testing techniques and density functional theory(DFT)calculations.It is found that the nitrogen-rich Mo_(x)N as the substrate is the basis of long cycling stability,and the few-layered MoSe_(2) are the key to improving actual capacity.This work indicates that the decoration of few-layered selenides has a broad application prospect in high-performance metal-ion batteries.展开更多
基金supported by the National Natural Science Foundation of China(No.U21A2077)the Taishan Scholar Project Foundation of Shandong Province(No.ts20190908)the Natural Science Foundation of Shandong Province(Nos.ZR2021ZD05,ZR2022QB200).
文摘Transition metal dichalcogenides are attractive anode materials for sodium ion batteries(SIBs)due to their high theoretical capacity and large interlayer spacing.However,its practical application is hampered by the sluggish kinetics of Na^(+)insertion and structure collapse caused by Na^(+)insertion/deinsertion.Herein,the heterostructures of MoSe_(2) nanosheets vertically growing on bowl-like carbon(MoSe_(2)@C)are designed and prepared by a template method coupled with selenization treatment to boost storage sodium performance.The hollow and collapse could provide enough storage space for Na^(+)and alleviate the volume expansion during the charge/discharge processes.MoSe_(2) nanosheets vertically grown on carbon could expose more active sites for adsorbing Na^(+)to enhance the utilization rate of electrode materials.Moreover,building heterostructures by combining different phase components could facilitate Na^(+)diffusion and advance reaction kinetics.Benefiting from these merits,the bowl-like MoSe_(2)@C shows outstanding reversible capacity(356.8 mAh·g^(-1) after 1500 cycles at 1 A·g^(-1))and remarkable rate performance(249.9 mAh·g^(-1)10 A·g^(-1)).
基金financially supported by the National Natural Science Foundation of China(No.52173055)the Natural Science Foundation of Shanghai(No.19ZR1401100)+1 种基金the Fundamental Research Funds for the Central UniversitiesDHU Distinguished Young Professor Program(No.LZA2020001)。
文摘NH_(3) plays an essential role in human life since it is an important raw material for fertilizers,plastics and rubbers production.As an NH_(3) synthesis technology under ambient conditions,electrocatalytic N_(2) reduction reaction(NRR)has great potential to replace the energy-intensive Haber-Bosch process.The key of electrocatalytic NRR is the exploration of efficient catalysts.Transition metal Mo is promising since it exists naturally in nitrogenase due to the unique Mo-N_(2) interaction;particularly in the form of 2D material such as MoSe_(2),the surface area is maximized for more active sites.However,the NRR performance of MoSe_(2) is still unsatisfactory because Mo is only exposed at the semi-open edge,and the electronegative Se-mantled surface area remains inaccessible to N_(2).Herein,we propose a simple and effective strategy to create high-concentration Se vacancies in MoSe_(2) through heteroatom doping induced lattice strain,which effectively enhances the Mo-N_(2) interaction on the surface area.In result,high NH_(3) yield(3.04×10^(–10)mol s^(–1)cm^(–2))and Faraday efficiency(21.61%)are attained at–0.45 V vs.RHE in 0.1 mol/L Na_(2)SO_(4).
基金supported by the National Natural Science Foundation of China(52171207,51762021)the Natural Science Foundation of Jiangxi province(20212BAB204031,20192ACB21009)。
文摘Transition metal nitrides have become the focus of research in sodium ion batteries(SIBs)due to their unique metal properties and high theoretical capacity.However,the low actual capacity is still the main bottleneck for their application.Herein,using Mo-aniline frameworks as precursors,the carbon encapsulated nitrogen-rich Mo_(x)N is decorated by few-layered MoSe_(2) nanosheets(MoSe_(2)@Mo_(x)N/C-I)after the facile calcinating,selenizing,and nitriding.The carbon encapsulation can effectively strengthen the structural stability of Mo_(x)N.The nitrogen-rich Mo_(x)N and decoration of few-layered MoSe_(2) can create rich heterointerfaces and extra active sites for rapid sodium-ion storage,thus promoting reaction kinetics and improving actual capacity.The MoSe_(2)@Mo_(x)N/C-I as an anode achieves a large reversible capacity of 522.8 mAh g^(-1)at 0.1 A g^(-1),and 254.3 mAh g^(-1)capacity is obtained after 6000 cycles at 5.0 A g^(-1),showing signally improved sodium-ion storage properties.The storage mechanisms and kinetic behaviors are described systematically via the advanced testing techniques and density functional theory(DFT)calculations.It is found that the nitrogen-rich Mo_(x)N as the substrate is the basis of long cycling stability,and the few-layered MoSe_(2) are the key to improving actual capacity.This work indicates that the decoration of few-layered selenides has a broad application prospect in high-performance metal-ion batteries.
