Amorphous Domains in Black Titanium Dioxide

Abstract Although oxygen vacancies (O v s) play a critical role for many applications of metal oxides, a controllable synthetic strategy for anisotropic O v s remains a great challenge. Here, a novel strategy is proposed to achieve the regional dual structure with anisotropic O v s at both the surface and in the interior of TiO 2 by constructing amorphous domains. The as‐prepared black TiO 2 with amorphous domains exhibits superior activity in degrading rhodamine B (RhB) solutions, which can instantly decompose RhB with just a shake. First‐principle simulations reveal that subsurface O v s in TiO 2 are energetically favored, resulting in the formation of amorphous domains in the interior region via diffusion of surface‐formed O v s into the subsurface. The stable O v ‐induced amorphous domains in TiO 2 with enhanced catalytic performances provide a scalable strategy to practical O v engineering in functional metal oxides.