Solution Plasma Process-Derived Defect-Induced Heterophase Anatase/Brookite TiO(2) Nanocrystals for Enhanced Gaseous Photocatalytic Performance

[Image: see text] We report a simple room-temperature synthesis route for increasing the reactivity of a TiO(2) photocatalyst using a solution plasma process (SPP). Hydrogen radicals generated from the SPP chamber interact with the TiO(2) photocatalyst feedstock, transforming its crystalline phase and introducing oxygen vacancy defects. In this work, we examined a pure anatase TiO(2) as a model feedstock because of its photocatalytic attributes and well-characterized properties. After the SPP treatment, the pure anatase crystalline phase was transformed to an anatase/brookite heterocrystalline phase with oxygen vacancies. Furthermore, the SPP treatment promoted the absorption of both UV and visible light by TiO(2). As a result, TiO(2) treated by the SPP for 3 h showed a high gaseous photocatalytic performance (91.1%) for acetaldehyde degradation to CO(2) compared with the activity of untreated TiO(2) (51%). The SPP-treated TiO(2) was also more active than nitrogen-doped TiO(2) driven by visible light (66%). The overall photocatalytic performance was related to the SPP treatment time. The SPP technique could be used to enhance the activity of readily available feedstocks with a short processing time. These results demonstrate the potential of this method for modifying narrow-band gap metal oxides, metal sulfides, and polymer composite-based catalyst materials. The modifications of these materials are not limited to photocatalysts and could be used in a wide range of energy and environment-based applications.