Unexpectedly High Capacitance of the Metal Nanoparticle/Water Interface: Molecular‐Level Insights into the Electrical Double Layer. Issue 5 (17th December 2021)

• Record Type: Journal Article
• Authors: Azimzadeh Sani, Mahnaz; Pavlopoulos, Nicholas G.; Pezzotti, Simone; Serva, Alessandra; Cignoni, Paolo; Linnemann, Julia; Salanne, Mathieu; Gaigeot, Marie‐Pierre; Tschulik, Kristina
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 5(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-17
• Subjects: electrical double-layer capacitance -- nano-impact electrochemistry -- nanoparticles -- solid–liquid interface; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202112679
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The electrical double‐layer plays a key role in important interfacial electrochemical processes from catalysis to energy storage and corrosion. Therefore, understanding its structure is crucial for the progress of sustainable technologies. We extract new physico‐chemical information on the capacitance and structure of the electrical double‐layer of platinum and gold nanoparticles at the molecular level, employing single nanoparticle electrochemistry. The charge storage ability of the solid/liquid interface is larger by one order‐of‐magnitude than predicted by the traditional mean‐field models of the double‐layer such as the Gouy–Chapman–Stern model. Performing molecular dynamics simulations, we investigate the possible relationship between the measured high capacitance and adsorption strength of the water adlayer formed at the metal surface. These insights may launch the active tuning of solid–solvent and solvent–solvent interactions as an innovative design strategy to transform energy technologies towards superior performance and sustainability. Abstract : Nano‐impact electrochemistry revealed an anomalously high capacitance for Pt nanoparticles and to a lower extent for Au nanoparticles at potentials more negative than their potential of zero charge. MD calculations showed that the strong interaction of metal with water molecules leads to water chemisorption and accumulation of ions in the Helmholtz layer beyond expectation, resulting in a higher interface charge storage ability.