Collectively, the key findings of this work demonstrate similarity between the in situ LP-TEM and complementary ex situ experimental observations and were reconciled through the lens of plasmonic hot carrier-mediated redox chemistry. The work additionally revealed surface rearrangement of Au to occur alongside hot electron induced Ag deposition, potentially due to inefficient hole scavenging by IPA (Figure ). Furthermore, we found that water contamination can profoundly alter and override the nanorod growth dynamics considered attributable to plasmonic hot carriers. As such, future work may explore use of hole scavengers that are more effective and/or readily soluble in toluene. Citrate ions are widely utilized as a hole scavenger in plasmon-mediated synthesis of metallic nanostructures, 109,110 but are not soluble in the solvent mixture used here. Therefore, more non-polar carboxylic acids and derivatives may be favorable to implement for hole scavenging. An additional potential lever to explore is using thiolated scavengers to enhance access to holes by ensuring coordination to Au particle surfaces via the