Catechol and Its Derivatives Adhesion on Graphene: Insights from Molecular Dynamics Simulations

Understanding the interactions between aromatic compounds and organic surfaces is vital for adhesion applications. In this work, molecular dynamics simulations are employed to study the adhesion of substituted aromatic compounds on graphene and hydroxylated graphene surfaces. Effects of substituent groups, the number and position of hydroxyl groups, the number of graphene layers and adsorbate concentration on adhesion are discussed. Simulation results indicate that both electron-donating and electron-withdrawing on the benzene ring could enhance the adhesion to graphene, and hydroxyl groups have a strong effect for aromatic ring’s adsorption on graphene. Further analyses show that the adsorption affinities enhance as the number of hydroxyl group increases. The effect caused by the distribution of hydroxyl groups on aromatic ring is weaker than that of hydroxyl group number. At low adsorbate concentration, only monolayer adsorption occurs. In addition, we also found that the adsorption hydroxyl-substituent benzenes onto hydroxylated graphene was dominated by van der Waals interactions. With the hydroxyl group density on graphene increasing, π–π interactions between the aromatic groups and graphene descend. The arrangement of hydroxyl groups on graphene has great influence on adhesion. A linear correlation is found between the potential of mean force via umbrella sampling and rupture force obtained from steered molecular dynamics simulations for catechol and its derivatives adsorbed on graphene. This work may provide some guidance for the selective removal of environmental contaminants through graphene