Water-Dispersible Nanocrystal Assemblies: From Synthesis to Energy Catalysis Applications

Abstract Nanocrystals (NCs) and their assembled supracrystals (SCs) serve as a unique ambassador between the disciplines of physics and chemistry. They embody the rigorous principles of quantum confinement at the nanoscale while showcasing the structural elegance and programmability inherent to chemical synthesis. This convergence enables the deep integration of “scale manipulation” and “interface engineering,” facilitating directed, low-loss, and finely tunable energy conversion and mass transfer. The core advantage lies in their designable architectures and the emergent multiscale collective properties. At the NC level, precise control over size, composition, and surface chemistry tailors active sites, electronic structure, and surface affinity, directly addressing fundamental challenges in catalytic activity and selectivity. At the SC level, long-range ordering, engineered porosity, and coherent interfaces collectively optimize electron transport, mass diffusion, and collective responses, thereby tackling critical issues of catalytic efficiency and stability. This review first elucidates how assembly methodologies and interfacial forces dictate the superlattice architecture, which in turn governs the efficiency of energy transfer, conversion, and mass transport. Finally, we present their transformative applications in energy catalysis, including photocatalysis and electrocatalysis for molecular transformation, aiming to chart a course for the rational design of next-generation, high-performance catalytic materials.