TiO ₂ 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 TiO 2 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 Ti 3+ ). It thus demonstrates excellent performance in photocatalytic degradation and UV shielding, outperforming conventional sol‐gel‐derived TiO 2 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.