In this study,two-dimensional V2CTx MXene has been prepared by selectively etching Al layers from V2 AlC MAX phase by NaF+HCl etching at 90℃for 72 h and its performance as supercapacitor(SC)electrode were tested usin...In this study,two-dimensional V2CTx MXene has been prepared by selectively etching Al layers from V2 AlC MAX phase by NaF+HCl etching at 90℃for 72 h and its performance as supercapacitor(SC)electrode were tested using simulating seawater as electrolyte.V2CTx MXene-based electrodes shows a good capacitance of 181.1 F/g,which is in accordance with the volumetric specific capacitance of 317.8 F/cm^3,and with 89.1%capacitance retention even after 5000 cycle.Compared with other MXenes,V2CTx have better electrochemical performance as SC electrode.This work provides an innovative strategy to apply V2CTx MXene as SC electrode in safety and effective seawater electrolyte.展开更多
Although MXenes is highly attractive as anode materials of lithium ion batteries,it sets a bottleneck for higher capacity of the V2CTxMXene due to the limited interlayer space and the derived surface terminations.Here...Although MXenes is highly attractive as anode materials of lithium ion batteries,it sets a bottleneck for higher capacity of the V2CTxMXene due to the limited interlayer space and the derived surface terminations.Herein,the cation intercalation and ion-exchange were well employed to achieve a K+and Ca2+intercalated V2CTxMXene.A larger interlayer distance and low F surface terminations were thereof obtained,which accelerates the ion transport and promotes the delicate surface of V2CTx MXene.As a result,a package of enhanced capacity,rate performance and cyclability can be achieved.Furthermore,the ion exchange approach can be extended to other 2 D layered materials,and both the interlayer control and the surface modification will be achieved.展开更多
MXene材料由于其独特的二维结构在储能领域受到了广泛的关注.通过对V 2AlC陶瓷粉体中Al层原子的选择性刻蚀可以制备出V2CTx二维纳米材料,其作为锂离子电池负极材料具有高的理论比容量,然而其刻蚀过程较为困难,且刻蚀产物表面的官能团显...MXene材料由于其独特的二维结构在储能领域受到了广泛的关注.通过对V 2AlC陶瓷粉体中Al层原子的选择性刻蚀可以制备出V2CTx二维纳米材料,其作为锂离子电池负极材料具有高的理论比容量,然而其刻蚀过程较为困难,且刻蚀产物表面的官能团显著影响其电化学性能.本论文采用HF以及HCl/NaF这两种刻蚀剂制备出了V2CTx二维材料,利用XRD、SEM、EDS和电化学工作站研究了其晶相、形貌结构和电化学性能.结果表明,采用HF做刻蚀剂得到的V2CTx在大电流密度下具有较好的循环性能,在0.1 A g-1的电流密度下循环100次,放电比容量分别为248 mAh g-1;在1A g-1的电流密度下循环1000次,可逆比容量分别为94 mAh g-1.展开更多
MXene V_(2)CT_(x) has great practicability because it is not easy to degrade under ambient conditions.In this paper,a V_(2)CT_(x) saturable absorber(SA)was firstly applied to a passively Q-switched(PQS)laser,to the be...MXene V_(2)CT_(x) has great practicability because it is not easy to degrade under ambient conditions.In this paper,a V_(2)CT_(x) saturable absorber(SA)was firstly applied to a passively Q-switched(PQS)laser,to the best of our knowledge.The V_(2)CT_(x)-SA was prepared by the spin-coating method.The linear absorption of the V_(2)CT_(x)-SA in the 1000-2200 nm region and the nonlinear absorption near 2μm were studied.With the V_(2)CT_(x)-SA,a typical PQS operation at 1.94μm was realized in a Tm:YAlO3laser.The minimum pulse width produced by the PQS laser was 528 ns,and the peak power,repetition rate,and average output power were 10.06 W,65.9 kHz,and 350 mW,respectively.Meanwhile,the maximum pulse energy was 6.33μJ.This work demonstrates that the V_(2)CT_(x) can be used as an effective SA to obtain nanosecond pulses with high peak power and high repetition rate simultaneously.展开更多
基金supported by the National Natural Science Foundation of China(No.51772077)Program for Innovative Research Team(in Science and Technology)in the University of Henan Province(No.19IRTSTHN027)+2 种基金Natural Science Foundation of Henan Province(Nos.182300410228 and 182300410275)the China Postdoctoral Science Foundation(No.2019M652537)Henan Postdoctoral Foundation(No.19030065)。
文摘In this study,two-dimensional V2CTx MXene has been prepared by selectively etching Al layers from V2 AlC MAX phase by NaF+HCl etching at 90℃for 72 h and its performance as supercapacitor(SC)electrode were tested using simulating seawater as electrolyte.V2CTx MXene-based electrodes shows a good capacitance of 181.1 F/g,which is in accordance with the volumetric specific capacitance of 317.8 F/cm^3,and with 89.1%capacitance retention even after 5000 cycle.Compared with other MXenes,V2CTx have better electrochemical performance as SC electrode.This work provides an innovative strategy to apply V2CTx MXene as SC electrode in safety and effective seawater electrolyte.
基金financial support provided by the National Natural Science Foundation of China(No.51932005)Liao Ning Revitalization Talents Program(XLYC1807175)+4 种基金the Joint Research Fund Liaoning Shenyang National Laboratory for Materials Science(SYNL)(20180510047)the Research Fund of SYNL(L2019F38)the Youth Innovation Promotion Association CAS(2015152)the Program for the Development of Science and Technology of Jilin Province(No.20190201309JC)the Project of Development and Reform Commission of Jilin Province(No.2019C042-1)。
文摘Although MXenes is highly attractive as anode materials of lithium ion batteries,it sets a bottleneck for higher capacity of the V2CTxMXene due to the limited interlayer space and the derived surface terminations.Herein,the cation intercalation and ion-exchange were well employed to achieve a K+and Ca2+intercalated V2CTxMXene.A larger interlayer distance and low F surface terminations were thereof obtained,which accelerates the ion transport and promotes the delicate surface of V2CTx MXene.As a result,a package of enhanced capacity,rate performance and cyclability can be achieved.Furthermore,the ion exchange approach can be extended to other 2 D layered materials,and both the interlayer control and the surface modification will be achieved.
文摘MXene材料由于其独特的二维结构在储能领域受到了广泛的关注.通过对V 2AlC陶瓷粉体中Al层原子的选择性刻蚀可以制备出V2CTx二维纳米材料,其作为锂离子电池负极材料具有高的理论比容量,然而其刻蚀过程较为困难,且刻蚀产物表面的官能团显著影响其电化学性能.本论文采用HF以及HCl/NaF这两种刻蚀剂制备出了V2CTx二维材料,利用XRD、SEM、EDS和电化学工作站研究了其晶相、形貌结构和电化学性能.结果表明,采用HF做刻蚀剂得到的V2CTx在大电流密度下具有较好的循环性能,在0.1 A g-1的电流密度下循环100次,放电比容量分别为248 mAh g-1;在1A g-1的电流密度下循环1000次,可逆比容量分别为94 mAh g-1.
基金supported by the China Postdoctoral Science Foundation(No.2020M670937)the Basic Scientific Research Business Expenses of Colleges and Universities in Heilongjiang Province(No.2021-KYYWF-0020)。
文摘MXene V_(2)CT_(x) has great practicability because it is not easy to degrade under ambient conditions.In this paper,a V_(2)CT_(x) saturable absorber(SA)was firstly applied to a passively Q-switched(PQS)laser,to the best of our knowledge.The V_(2)CT_(x)-SA was prepared by the spin-coating method.The linear absorption of the V_(2)CT_(x)-SA in the 1000-2200 nm region and the nonlinear absorption near 2μm were studied.With the V_(2)CT_(x)-SA,a typical PQS operation at 1.94μm was realized in a Tm:YAlO3laser.The minimum pulse width produced by the PQS laser was 528 ns,and the peak power,repetition rate,and average output power were 10.06 W,65.9 kHz,and 350 mW,respectively.Meanwhile,the maximum pulse energy was 6.33μJ.This work demonstrates that the V_(2)CT_(x) can be used as an effective SA to obtain nanosecond pulses with high peak power and high repetition rate simultaneously.
