Progress in research on two-dimensional metal carbide nano sheet derivatives of Dalian Institute of Chemical Engineering

Recently, Wu Zhongshuai, a researcher in the research group of two-dimensional materials and energy devices of Dalian Institute of Chemical Physics, Chinese Academy of Sciences, developed a new strategy of simultaneous oxidation and alkalization In one step, the transformation of two-dimensional metal carbide nano chip (Ti3C2 mxene) to ultra-thin sodium titanate or potassium titanate nano belt was realized, and it was found that it has excellent sodium and potassium storage performance The research results were published on ACS Nano (DOI: 10.1021 / acsnano 7b01165) Progress in the research on the derivatives of 2D metal carbide nanoflakes of Dalian Institute of Chemistry (source: ACS Nano) mxene is a new type of 2D metal carbide (nitrogen) nanoflakes with excellent electrochemical performance, which is generally prepared by chemical etching and stripping of ternary Max phase, in which m refers to transition metals (such as Ti, V, Nb, Ta, etc.), a refers to Al, Si, etc., and X refers to C, N, etc The common Ti3C2 mxene surface has a large number of oxygen-containing / fluorine functional groups, which are easy to produce large irreversible capacity when used as energy storage electrode materials, resulting in low reversible specific capacity and coulomb efficiency Therefore, it is necessary to develop new mxene based electrode materials with stable structure and performance By designing a new process of oxidation and alkalization at the same time, the research team realized the transformation from two-dimensional metal carbide nano sheet (mxene) to ultra-thin sodium titanate or potassium titanate nano belt in one step The prepared nano belt has large layer spacing (0.90 ~ 0.93 nm), ultra-thin thickness (< 11 nm), and narrow width (< 60 nm) Nm) and the open macroporous structure are conducive to the rapid transport of electrolyte ions and the stability of the structure Therefore, the specific capacity of the nanoribbons is up to 191 MAH g-1 at the current density of 200 Ma g-1 The potassium titanate nanoribbons have excellent cycle stability, more than 900 stable cycles and high specific capacity, which is obviously superior to other titanium based nanomaterials It is important to note that Ti3C2 is only one of more than 60 mxene families, so this work has opened up a new way for the development of new mxene derived functional nanomaterials The above work was supported by national key research and development plan, National Natural Science Foundation, National Youth thousand talents plan, Liaoning Natural Science Foundation, China Postdoctoral fund and other projects Paper link: http://pubs.acs.org/doi/abs/10.1021/acsnano.7b01165