Role of the Hydration Shell in the pH-Dependent Adsorption of Maleic Acid

Past model studies have investigated adsorption processes on carbonaceous surfaces, focusing on gas-phase adsorption and thus uncharged molecules. In real-world applications, the adsorption from solutions is oftentimes of higher interest though, bringing charged species into the equation. In aqueous solutions, the first water layer with its stabilizing hydrogen bonds is especially important for the overall stability of the system. In this study, we use ab initio density functional theory for modeling the adsorption of (charged) maleic acid on a graphene sheet along with experimental validation of the computational results. We find that including a water layer makes a substantial difference in the conformation of charged adsorbed molecules. The results obtained are also in good agreement with the corresponding experiments.

Automated summary

The study investigates the adsorption of charged maleic acid on a graphene sheet, demonstrating that including a water layer significantly alters the conformation of charged adsorbed molecules and enhances the overall stability of the system. The experimental validation of the computational results shows good agreement with the study's findings.