Catalytic Activity Modulation and Field Effects in 2D-Confined Metals via van der Waals Heterostructures

Van der Waals heterostructures present a novel pathway to engineering catalytic properties in 2D-confined metals, particularly through work function modulation at the interface. In this study, we systematically explore the influence of underlying substrates and electric field permeation (from a poled ferroelectric substrate) on electrochemically grown 2D-confined metal catalysts on graphene, using surface-limited redox replacement (SLRR).

By employing a combination of X-ray absorption spectroscopy (XAS) and ultraviolet photoelectron spectroscopy (UPS) for work function measurements, we examine the interplay between the electric field effects transmitted through the graphene and the catalytic behavior of the 2D metal overlayer. The correlation between substrate-induced modifications to the work function and the electronic environment at the interface plays a pivotal role in determining the performance of catalytic reactions, such as the hydrogen evolution reaction (HER) and carbon dioxide reduction reaction (CO2RR). These observations align with our previous findings on metal-graphene-metal systems and extend our understanding to cases with low-conductivity substrates/insulators, highlighting the versatility of graphene as a template for electrochemical metal growth.

This study highlights the importance of controlling the interfacial properties in van der Waals heterostructures to enhance catalytic activity. The ability to modulate catalytic behavior through field effects and work function changes in 2D-confined metals provides valuable insights for the development of tunable catalysts in sustainable electronics applications.