P-014

Sorour Semsari Parapari

sorour.semsari.parapari@ijs.si

Layrton José Souza da Silva, Monica Parpal, Jon Ustarroz, Saso Sturm

Jozef Stefan Institute, Slovenia

Real-Time Dynamics of Copper Nanoparticle Growth by In-Situ Electrochemical liquid-cell TEM

Recently, the electrochemical deposition on low-energy substrates and the electrochemical stability of the bulk and nano-deposits have been the subject of numerous in-depth studies for better synthesis control of nanostructured electrocatalysts and their durability in electrochemical technologies. Electrodeposition studies of nanomaterials are conventionally investigated over large specimen areas. The thermodynamics and kinetics of both NP nucleation and growth are affected by the specific surface interactions between NPs and substrate, which depend on the heterogeneous substrate's properties. A direct visualization of growth and/or dissolution at high-spatial resolution allows us to have a better understanding of these processes. Recently developed liquid-cell transmission electron microscope (TEM) holders allow for in-situ studying of materials reactions. Such specialized holders contain liquid cells that can withhold the liquid in a confined environment, allowing the imaging and spectroscopy of samples in the reaction media. Combining the capabilities of liquid-cell TEM holders with micro-size electrodes printed on a chip enables us to study dynamic phenomena during electrochemical reactions at high spatial and temporal resolution with the in-situ Electrochemical Liquid Transmission Electron Microscopy (in-situ EC-LTEM). In this work, we have employed the EC-LC TEM to directly visualize the dynamic growth of copper nanoparticles as an important catalyst for CO2 electrochemical reduction reaction.

The in-situ EC-LC TEM experiments were performed using at a 200 kV accelerating voltage in the bright-field TEM mode. Experimental images and videos were recorded at the standard illumination conditions for the real-time imaging. The electrochemical measurements in the TEM were carried out using a Protochips Poseidon 500 liquid holder, which allows observation of dynamic electrochemical processes in the liquid. The electrodeposition process of Cu nanoparticles was conducted from a solution of CuSO4 in ultrapure deionized water.

The unprecedented combination of EC-LC TEM and the macro-scale experiments revealed important information from the electrochemical deposition and dissolution of supported metal NPs. This approach opens up new opportunities for the rational design of functional nanostructured materials based on their morphology and structural functionalities.