CO2-Induced Two-Dimensional Amorphous TiO2 and Its Excellent Film-Forming Properties

Fabrication of amorphous transition metal oxides (TMOs) is necessary to explore their functionality for potential applications, while it is challenging for this type of inorganic materials. Finding an ideal and efficient route for their amorphization is in anticipation. Herein, as a typical non-layered TMO, two-dimensional amorphous TiO2(B) has been successfully fabricated with the assistance of supercritical CO2 (SC CO2). Depending on multi-level theoretical simulations, it demonstrates that the defect regions in TiO2(B) are favorable for CO2 to exert its amorphization effect. Therefore, it provides a new insight into understanding the microscopic mechanism of SC CO2 to functionalize non-layered TMOs. Further, stable optically transparent thin films based on the as-prepared samples were conveniently obtained, and their excellent optical stability is also identified.