Mechanistic Insights and Strategic Assembly of Tailored Novel Oxide‐Phosphide Heterostructure Nanocrystals

The strategic design of heterostructure nanocrystals with controlled interfaces and compositions is a cornerstone for advancing catalytic and energy‐related applications. However, a comprehensive understanding of the underlying mechanisms governing the growth and functionality of these systems remains a significant bottleneck. Herein, a detailed mechanistic investigation and a strategic synthetic approach is presented for the synthesis of In₂O₃@Cu_2.7 P oxide‐phosphide heterostructures via facile one‐pot hot‐injection method. This synthesis strategy takes advantage of the differing redox potentials and reactivities of the precursors to sequentially nucleate and control the growth of distinct domains, a challenging feat in a one‐pot synthesis. This self‐regulated mechanism with the initial in situ formation of copper seeds, followed by the growth of In₂O₃ on the copper surface and the controlled phosphorization of the copper domains, underscores the complex interplay between nucleation kinetics, growth processes, and interfacial energies. Through comprehensive structural and electrochemical characterization, this study offers invaluable insights into the growth mechanism, bridging a critical gap in understanding. The synthesized heterostructures are explored for their catalytic activity in the oxygen reduction reaction. This study provides a robust and predictive framework for the strategic design of advanced heterostructures with tunable functionalities for catalytic and energy conversion applications.