Construction of complex metal nanoparticles via solid-phase ion diffusion for sustainable catalysis

Metal nanoparticles (MNPs) with complex structure and uniform distribution demonstrate interesting physicochemical properties and thus are widely applied. The traditional wet chemistry methods are commonly applied to construct MNPs structure, yet they still exhibit limitations in the liquid-phase environment, particularly, for synthesis of supported MNPs in one-step process. Diverse synthesis strategies have been investigated to design complex MNPs in a more efficient manner, among which the thermal treatment atmosphere induced solid-phase ion diffusion (TASID) synthesis strategy serves as an attractive strategy. This review summaries recent progresses of complex MNPs construction via TASID synthesis strategy, which realize the structure design through thermally treating the precursors under various gas atmosphere, such as oxidative, reductive, carbonaceous, and inert gas. This TASID strategy can both achieve the MNPs structure design and uniform dispersion simultaneously, demonstrating its unique properties. MNPs with diverse composition and structure, such as hollow, core@shell, yolk@shell, Janus, and multi-chamber structure, are successfully synthesized. The TASID synthesis mechanisms of galvanic replacement, Kirkendall effect, Ostwald ripening, carburization, and exsolution are elaborated in detail. The synthesis-mechanism-structure correlation of TASID is identified and the applications of these constructed MNPs are presented. This strategy could be developed into a class of synthetic methods by applying various thermal gas.