Chemical and Engineering Materials Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
Materials Science and Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
ACS Appl Mater Interfaces. 2016 Apr 13;8(14):8859-63. doi: 10.1021/acsami.6b01490. Epub 2016 Mar 30.
MXenes are a recently discovered class of 2D materials with an excellent potential for energy storage applications. Because MXene surfaces are hydrophilic and attractive interaction forces between the layers are relatively weak, water molecules can spontaneously intercalate at ambient humidity and significantly influence the key properties of this 2D material. Using complementary X-ray and neutron scattering techniques, we demonstrate that intercalation with potassium cations significantly improves structural homogeneity and water stability in MXenes. In agreement with molecular dynamics simulations, intercalated potassium ions reduce the water self-diffusion coefficient by 2 orders of magnitude, suggesting greater stability of hydrated MXene against changing environmental conditions.
MXenes 是一类最近发现的二维材料，在储能应用方面具有优异的潜力。由于 MXene 表面亲水，层间的吸引力较弱，水分子可以在环境湿度下自发地插层，并显著影响这种二维材料的关键性质。我们使用互补的 X 射线和中子散射技术证明，与钾离子的插层显著提高了 MXenes 的结构均一性和水稳定性。与分子动力学模拟一致，插层的钾离子将水的自扩散系数降低了两个数量级，这表明水合 MXene 对环境条件变化的稳定性更高。
