MoS2/硼掺杂石墨烯的电化学析氢和储锂性能

MoS2/B-doped graphene for electrochemical hydrogen evolution and lithium storage

为了研发高效低成本的析氢反应(HER)电催化剂和高性能的电化学储锂电极材料,通过一步水热法制备MoS2/硼掺杂石墨烯(MoS2/BG)复合材料.结果表明,少堆积MoS2纳米片均匀地分散在硼掺杂石墨烯上,并具有较多的无序结构和扩大的层间距.作为析氢反应电催化剂,MoS2/BG复合材料表现出较高的电催化活性和较低的Tafel斜率(46.3 mV/dec);作为电化学储锂电极材料,MoS2/BG复合材料表现出优异的电化学储锂性能,可逆比容量为1 205 mA·h/g,并具有稳定的循环性能和显著增强的高倍率特性.MoS2/BG复合材料电化学性能优异是由于硼掺杂改变石墨烯的电子性质和表面特性,以及无序结构较多的弱堆积MoS2层均匀地分散在硼掺杂石墨烯表面,增加电催化析氢反应的活性位点和电化学储锂能力,降低电极反应的电子转移阻抗,增强电极反应的动力学性能.

MoS2/B-doped graphene composites(MoS2/BG)were prepared by one-step hydrothermal method,in order to develop high-efficiency and low-cost electrocatalyst for hydrogen evolution reaction(HER)and highperformance lithium storage electrode material.Results show that the poor-stacked MoS2 nanosheets with more disordered structures and expanded interlayer distance are well dispersed on the surface of B-doped graphene sheets.MoS2/BG composite shows high electrocatalytic activity with low Tafel slope(46.3 mV/dec)as HER electrocatalyst.MoS2/BG composite shows excellent lithium storage performance as a lithium storage electrode material.It can exhibit a reversible capacity as high as 1205 mA·h/g with stable cycle performance and significantly enhanced high rate capability.The excellent electrochemical performance of MoS2/BG composite is due to the fact that boron doping modifies the electronic and surface properties of graphene,and the poor-stacked MoS2 layers with more disordered structures are uniformly dispersed on the surface of B-doped graphene,which not only increases the active sites for HER and electrochemical lithium storage capability,but also reduces the electron transfer impedance of the electrode reaction,leading to the enhancement of electrode reaction kinetics.