Cadmium Sulfide‐Based Nanostructures for Next‐Generation Multifunctional Applications: Design Strategies, Decoding Performance Limitations, and Recent Advances

ABSTRACT Cadmium sulfide nanostructures have garnered significant attention due to their ideal visible light absorption and well‐positioned conduction/valence bands, enabling simultaneous oxidation and reduction reactions critical for diverse applications. However, the practical use of cadmium sulfide (CdS) nanostructures faces critical challenges, including rapid charge‐carrier recombination and severe photocorrosion, which compromise long‐term stability and reusability. This review decodes these performance limitations and critically assesses vital progress in design strategies for nanostructure engineering, including surface engineering, compositional tuning, and the use of sacrificial agents to mitigate these limitations while enhancing the efficiency and stability of CdS nanostructures. We also provide a systematic examination of CdS synthesis, with special emphasis on solution‐based routes, to establish structure–property–performance relationships. The recent advances in applications of CdS nanostructures are categorized across three key domains: (1) clean energy (batteries, supercapacitors, solar cells, H 2 evolution, CO 2 reduction); (2) environmental remediation (pollutant degradation, heavy metals removal); and (3) biomedical applications. Finally, this review highlights unresolved challenges, including scalability and mechanistic ambiguities, and proposes future directions to bridge lab‐scale innovations with real‐world applications.