Unexpectedly High Capacitance of the Metal Nanoparticle/Water Interface: Molecular‐Level Insights into the Electrical Double Layer

Abstract

The electrical double-layer playsakey role in important interfacial electrochemical processes from catalysis to energy storage and corrosion. Therefore,u nderstanding 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, employingsingle 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 doublelayer such as the Gouy-Chapman-Stern model. Performing molecular dynamics simulations,w ei nvestigate the possible relationship between the measured high capacitance and adsorption strength of the water adlayer formed at the metal surface.T hese insights may launch the active tuning of solidsolvent and solvent-solvent interactions as an innovative design strategy to transform energy technologies towards superior performance and sustainability.

Multiscale simulations of nanofluidics: Recent progress and perspective

“…The solvated ions and the molecular dipoles can also orient along the electric field induced by the interface, leading to local changes in polarity and thus in free energy of solvation or adsorption. 207 In nanochannels, the electrode kinetics at the EDL significantly deviates from the Gou-Chapmann-Stern model 208,209 and the EDL structures under biased potentials becomes unpredictable. 210…”

Stepwise dissolution of silica surface in alkaline solution revealed by molecular modeling

“…10 Water molecules near the charged silica surface behave differently compared to bulk water, as the hydrogen bond network becomes truncated, resulting in nontetrahedrally coordinated interfacial water. 11 In terms of the electrical double layer, the interfacial water molecules exhibit statistically consistent orientation and arrangement, causing their dipole moments to be oriented away from the negatively charged surface. [12][13][14] The unique properties of interfacial water in electrolyte solutions may play a significant role in governing the molecular mechanisms of silica dissolution.…”

“…The surface of silica typically exhibits a point‐of‐zero‐charge at pH ∼2, above which it becomes negatively charged 10 . Water molecules near the charged silica surface behave differently compared to bulk water, as the hydrogen bond network becomes truncated, resulting in non‐tetrahedrally coordinated interfacial water 11 . In terms of the electrical double layer, the interfacial water molecules exhibit statistically consistent orientation and arrangement, causing their dipole moments to be oriented away from the negatively charged surface 12–14 .…”

Formation of Molecular Junctions by Single-Entity Collision Electrochemistry

“…It is well worth noting that the current flourishing state of single-entity electrochemistry was reignited by Bard’s group following their paper which utilized the amplification factor during a continuous electrocatalytic proton reduction process on Pt NPs . The subsequent series of investigations into the nanoimpact phenomenon and electrocatalytic collisions showcase its potential utility in diverse fields, from energy conversion and storage to nanoelectronics, molecular devices, catalysis, and even biomedical applications. ,, Through the utilization of single-NP electrochemistry, novel physicochemical insights into the capacitance and structure of the electrical double-layer (EDL) at the electrode/electrolyte interface contributes were obtained, eliminating potential artifacts arising from film porosity or additives . Utilizing these insights, the dynamic adjustment of the electrode–electrolyte interface could emerge as a pioneering design strategy, revolutionizing energy technologies for enhanced performance and sustainability.…”