Solid-state self carbo-passivation for refurbishing colloidal dispersity of catalytic silica nanoreactors

• Published in: Materials horizons 2024-12
• Main Authors: Choi, Jeong Hun, Kumari, Nitee, Acharya, Anubhab, Kumar, Amit, Park, Sanghwang, Ro, Dongyeon, Seo, Jongcheol, Lee, Eunhye, Bae, Jee Hwan, Chun, Dong Won, Oh, Kyungtaek, Ryu, Sunmin, Lee, In Su
• Format: Article
• Language: English
• ISSN: 2051-6355; 2051-6355
• DOI: 10.1039/d4mh01623h

Silica-based nanostructures are among the most utilized materials. However, a persistent challenge is their irreversible agglomeration upon drying and heat treatments, restricting their homogeneous colloidal re-dispersion - a mandatory requirement for diverse bio-applications. We address this bottleneck by developing a self carbo-passivation (SCP) strategy: silica nanoparticles (NPs), pre-included with the catalytic metal precursors and organosilanes undergo thermochemical conversion with highly controlled interior-to-surface segregation of nanometer-scale "carbonaceous skin patches". This self-generated inert passivate shielding phenomenon at the individual NP level completely inhibits interparticle cross-linking, stopping chemical agglomeration and enhancing colloidal stability. By SCP, we synthesized silica-based magnetic-catalytic nanoreactors for magnetic field-induced catalysis inside living cells, by benefitting from the convenient high colloidal stability in bio-media, easy endocytosis and protective accessibility to the catalytic site in the complex bio-environment. The present work demonstrates deep mechanistic insight into unexplored solid-state nanoscopic chemical passivation phenomena, dramatically influencing NP surface characteristics, playing a critical role in solution-based applications.