Abstract

Boehmite, a layer-structured AlOOH, is one of the potential candidate materials for applications to catalysis, energy storage, gas separation, and optoelectronics. Typically, the intercalation of guest molecules to boehmite layers leads to a variety of novel properties that are useful for practical applications. Here, we study the interaction between alkyl molecules and boehmite layers in alkyl derivatives of boehmite by using first-principles density-functional-theory (DFT) calculations. Two kinds of alkyl derivatives of boehmite are investigated: methyl and ethyl derivatives. We employ two different van-der-Waals-corrected computational methods based on the DFT, namely, vdW-DF2 and PBE-D2. The interlayer binding energy of alkyl chains to boehmite layers is calculated and the equilibrium interlayer distance as a function of the number of carbons in the alkyl chain is obtained. The interlayer spacing taken from vdW-DF2 is found to be in better agreement with the experimental data than that taken from PBE-D2. The calculated configurations of alkyl groups intercalated between boehmite layers are also presented.