Engineering the Nanoparticle–Electrode Interface

The chemical modification of electrodes has been an active area of research for decades. As the complexity of electrode modification has increased, nanoparticle (NP)-functionalized electrodes have emerged as a rich field of interest for investigating important applications such as energy conversion and storage, amperometric sensing, and the electrocatalytic synthesis of molecules. To enhance the performance of these systems, strategies to define the NP–electrode interface using molecular linkers have been investigated. By exploiting the advances made in modifying electrode surfaces with molecular monolayers and the synthesis of precise molecularly functionalized NPs, design strategies have been developed to fabricate NP-functionalized electrodes with a defined molecular interface. In this review, we discuss the current interfacing strategies utilized when designing a NP-functionalized electrode with a molecular linker. In this context, this review explores the different structural features that result from a molecularly linked NP–electrode system and how each of these features impacts the overall electrochemical behavior of the system. Furthermore, each design strategy and resulting electrode composition are evaluated based upon attributes that are of broad interest for all applications: overall system stability, uniformity of the NP–electrode interface and resulting NP distribution, electronic communication between the NP and the electrode, and overall system tunability. Finally, we discuss the promise of NP-functionalized electrodes with a defined molecular interface for creating advanced, multifunctional materials for a wide range of applications.