First-principles study of carbon chain length on template activity and cerium carbonate crystal growth

Abstract

First-principles calculations were employed to investigate the influence of carbon chain length (n = 8, 16, 24, 48, 64) of the template agent C_n TAB on its activity and its adsorption behavior on the (020) crystal plane of Ce₂(CO₃)₃·8H₂O crystals. The results indicate that as the carbon chain length n increases, the molecular polarity of the templating agent decreases, the HOMO–LUMO energy gap widens, and the COHP value, based on particle number integration, tends towards negative values. C–N bond strength increased, template reactivity decreased, and the adsorption energy of the quaternary ammonium headgroup onto the carbonate crystal plane diminished. The adsorption energy order was C₆₄ TAB < C₄₈TAB < C₂₄TAB < C₁₆TAB < C₈TAB. The DOS peak position of the adsorption site N–O shifts towards lower energies, the population-weighted integral ICOHP value tends towards positive values, and the interaction between the templating agent and the crystal changes from spontaneous adsorption to repulsion, with the repulsive strength increasing. The quaternary ammonium headgroup.