On the voltage-controlled assembly of NP arrays at electrochemical solid/liquid interfaces

TL;DR

This paper provides a theoretical analysis of voltage-controlled self-assembly and disassembly of nanoparticle arrays at electrochemical interfaces, crucial for developing tunable nanoplasmonic devices.

Contribution

It offers a comprehensive theoretical framework combining electrostatic and van der Waals interactions to assess nanoparticle array stability under voltage control.

Findings

Arrays can be assembled or disassembled by voltage variation.

Electrostatic and van der Waals interactions determine stability.

Feasibility of electrochemical plasmonic applications is supported.

Abstract

Research in the field of nanoplasmonic metamaterials is moving towards more and more interesting and, potentially useful, applications. The present work tackles the problem of nanoparticle self-assembly at an electrochemical solid-liquid interface from a purely theoretical perspective. We perform a simplified, comprehensive analysis of the stability of a nanoparticle arrays under different conditions and assembly. From the Poisson-Bjerrum model of electrostatic interactions between a metallic nanoparticle and the electrode and between the nanoparticles at the electrode, as well the Hamaker-Lifshitz model of the corresponding van der Waals interactions, we reach some conclusions regarding the possibility to build arrays of charged nanoparticles on electrodes and disassemble them, subject to variation of applied voltage. Since system of this type have been shown, recently, to provide nontrivial electrotuneable optical response, such analysis is crucial for answering the question whether such scenarios of electrochemical plasmonics are feasible.