Identical‐Location Single‐Molecule Imaging Reveals Cocatalyst‐Induced Enhancement in Photocatalytic Activity

Abstract Incorporating cocatalysts into photocatalytic systems has been widely recognized as an effective way to accelerate catalytic reactions and boost catalytic efficiency. However, directly visualizing the cocatalytic effect in real‐time with nanometric precision remains a significant challenge. This study presents an advanced single‐molecule imaging technique, IL‐SMLM (identical‐location single‐molecule localization microscopy), to resolve and quantify the activity enhancements induced by Pt cocatalysts on bismuth oxybromide (BiOBr) photocatalysts with nanometric resolution. The findings demonstrate that Pt cocatalysts significantly enhance the photoreduction ability of both the basal plane and edges in BiOBr. Remarkably, the enhancement factor at the edges (≈4668) is 12‐fold higher than that of the basal plane. This preferential enhancement originates from structural differences, with the presence of compressive strain at edges facilitating more efficient charge separation and electron transfer in BiOBr; further, the preferential charge separation of the edge will be amplified while introducing a uniformly distributed Pt cocatalyst. The study highlights IL‐SMLM as a powerful tool for probing complex cocatalytic phenomena at the single‐molecule level and provides valuable insights for the rational design of high‐performance photocatalytic systems.