TiO2 Aerogels With 2D Holey Building Blocks.

Two-dimensional (2D) nanomaterials offer exceptional properties for constructing advanced macroscopic materials. However, when assembled into 3D architectures, nanosheet stacking often restricts mass transport and reduces accessible active sites. Introducing in-plane pores in 3D macroscopic materials constructed with 2D nanomaterials has still faced great challenge. Herein, we present a monolithic holey 2D TiO2 aerogel composed of graphene-like nanosheets, successfully synthesized via a one-step "chemical vapor infiltration-deposition" coupling with "template-removal-driven crystallization under spatial confinement" strategy. This aerogel integrates a crystalline anatase framework with a unique 2D holey building morphology (exposing the {111} facet), a high specific surface area, and abundant surface defects (oxygen vacancies and Ti3+). It thus demonstrates excellent performance in photocatalytic degradation and UV shielding, outperforming conventional sol-gel-derived TiO2 aerogels composed of nanoparticle aggregates. Moreover, this aerogel shows promise as a candidate for wave-transparent materials. Our strategy concurrently achieves pore creation, crystallization, and 3D structuring, moving beyond the conventional "sheet-first, pore-later" sequence and opening one door for synthesizing advanced porous oxide nanosheets and their macro-architectures.