Electrochemical techniques for visualizing photoelectrochemical processes at the nanoscale

Two-dimensional semiconductors (2DSCs) are attractive materials for a variety of applications in electronics, photovoltaics, and catalysis. Despite their promise, it is often unclear how the performance of 2DSCs is influenced by structural defects present in these materials such as atomic vacancies or step-edges. A better fundamental understanding of how such structural features influence the generation and transport of charge carriers in 2DSCs will be critical in the pursuit of improved practical devices moving forward. In this Opinion, we highlight how electrochemistry can be leveraged to reveal fascinating insights into the behavior of 2DSCs. Recent advancements in techniques for mapping the rate of photoelectrochemical processes at 2DSCs are outlined and salient experiments employing these techniques are discussed. We conclude with sharing our perspective on opportunities within this field moving forward.