Amorphous Domains in Black Titanium Dioxide.

Kang, Jianxin; Zhang, Yan; Chai, Ziwei; Qiu, Xiaoyi; Cao, Xingzhong; Zhang, Peng; Teobaldi, Gilberto; Liu, Li-Min et al. · Adv Mater · 2021

basic_science · Level V

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Abstract

Although oxygen vacancies (O<sub>v</sub> s) play a critical role for many applications of metal oxides, a controllable synthetic strategy for anisotropic O<sub>v</sub> s remains a great challenge. Here, a novel strategy is proposed to achieve the regional dual structure with anisotropic O<sub>v</sub> s at both the surface and in the interior of TiO<sub>2</sub> by constructing amorphous domains. The as-prepared black TiO<sub>2</sub> 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<sub>v</sub> s in TiO<sub>2</sub> are energetically favored, resulting in the formation of amorphous domains in the interior region via diffusion of surface-formed O<sub>v</sub> s into the subsurface. The stable O<sub>v</sub> -induced amorphous domains in TiO<sub>2</sub> with enhanced catalytic performances provide a scalable strategy to practical O<sub>v</sub> engineering in functional metal oxides.