Reaction-pathway resolved multimode imaging of electrocatalytic oxygen evolution on single silver nanowires@ITO Mott–Schottky junctions

Mott-Schottky junctions are considered an ongoing focus in electrocatalysis due to their unique ability to modulate charge distribution, thereby improving the performance of electrocatalysts. However, resolving the interfacial reaction mechanism with high spatiotemporal and chemical resolution <i>in situ</i> remains challenging. Herein, a time-synchronized multimode optical imaging platform is developed, realizing multi-perspective visualization of a model Mott-Schottky (MS) electrocatalytic system. The unique interfacial electrooxidation dynamics of the individual silver nanowires (AgNWs) on an ITO substrate (AgNWs@ITO) MS junction and associated electrocatalytic oxygen evolution reaction (OER) pathways are revealed. The MS effect has been proven to regulate the reaction mechanisms by redistributing interfacial charges, leading to the superoxide radical-mediated reaction pathway. Thus, the superoxide radical scavengers can exclusively exert regulatory effects on AgNWs@ITO. Moreover, the finding highlights the possible active role of ITO in electrocatalytic studies. The unveiled modulating effect of the Mott-Schottky nanostructure on the electrochemical reaction pathway shows the potential and importance of the multi-resolved imaging approach in analyzing fundamental mechanisms of heterogeneous catalysis.