Overbury Steven H, Kolesnikov Alexander I, Brown Gilbert M, Zhang Zhiyong, Nair Gokul S, Sacci Robert L, Lotfi Roghayyeh, van Duin Adri C T, Naguib Michael
Department of Mechanical & Nuclear Engineering , Penn State University , University Park , Pennsylvania 16802 , United States.
Department of Physics and Engineering Physics , Tulane University , New Orleans , Louisiana 70118 , United States.
J Am Chem Soc. 2018 Aug 15;140(32):10305-10314. doi: 10.1021/jacs.8b05913. Epub 2018 Aug 6.
MXenes are a new class of two-dimensional materials with properties that make them important for applications that include batteries, capacitive energy storage, and electrocatalysis. These materials can be exfoliated and delaminated to create high surface areas with interlayers accessibility. Intercalation is known to be possible, and it is critical for many applications including electrochemical energy storage, water purification, and sensing. However, little is known about the nature of the intercalant and bonding interactions between the intercalant within the MXene. We have investigated urea interaction within a titanium carbide based MXene using inelastic neutron scattering (INS) to probe the state of intercalated species. By comparison with reference materials, we find that under intercalation conditions urea decomposes readily, leading to intercalation of ammonium cations observable by INS and evolving carbon dioxide detected by infrared spectroscopy. Reactive molecular dynamics calculations were conducted to provide atomistic insights about reaction pathways and their energetics. These results have implications for understanding intercalation in active layered materials.
MXenes是一类新型二维材料，其特性使其在包括电池、电容式储能和电催化等应用中具有重要意义。这些材料可以被剥离和分层，以形成具有层间可及性的高表面积。已知插层是可行的，并且对于包括电化学储能、水净化和传感在内的许多应用至关重要。然而，关于插层剂的性质以及MXene内部插层剂之间的键合相互作用，人们了解甚少。我们使用非弹性中子散射（INS）研究了基于碳化钛的MXene中尿素的相互作用，以探测插层物种状态。通过与参考材料比较，我们发现，在插层条件下尿素很容易分解，导致INS可观测到铵阳离子的插层，并通过红外光谱检测到二氧化碳的释放。进行了反应性分子动力学计算，以提供关于反应途径及其能量学的原子层面见解。这些结果对于理解活性层状材料中的插层具有重要意义。
