Nanoscale water spray assisted synthesis of CAs@B-TiO2 core–shell nanospheres with enhanced visible-light photocatalytic activity

Increasing photoactive areas and oxygen vacancy to improve the separation and utilization of electrons and holes in a photocatalytic process are a guarantee for highly photocatalysis efficiency. In this work, we report a CAs@B-TiO2core-shell nanospheres via a nanoscale water spray assisted method to deposit of black titanium dioxide (B-TiO2) on carbon aerogel sphere (CAs) though slowly hydrolyzing of butyl titanate (e.g. TBOT) in an ethanol-water system. On this basis, furthermore, a facile one-step N2H4 · H2O treatment was used to introduces oxygen vacancies on the surface of TiO2coating layer forming black TiO2. Oxygen vacancies can extend the optical response range of the TiO2shell from the ultraviolet to the visible region, and increase conductivity and charge transport on the interface of core-shell structure. This study reveals the importance of surface oxygen vacancies for reducing band gaps and developing highly active photocatalysts under visible light.