Designer hydrogenated wrinkled yolk@shell TiO₂ architectures towards advanced visible light photocatalysts for selective alcohol oxidation

Smart architectures of TiO₂ are attracting increasing attention due to their outstanding properties in a broad range of fields. Herein, we report the preparation of an unprecedented yolk/shell wrinkled TiO₂ architecture with excellent photocatalytic activities under visible light irradiation. This method includes solvothermal, partial etching and hydrogen treatment sequential preparation steps. The solvothermal step leads to yolk@shell TiO₂ (Y@S-TiO₂) structures which can generate multiple reflections of incident light so as to promote an efficient light harvesting due to an enhanced surface area and light scattering ability based on the hydrothermal alkaline partial etching. The hydrogen treatment process generated Ti³⁺ species on the surface of TiO₂ which facilitate electron-hole separation, decreasing the band gap of titania to the visible region. The resultant yolk@hydrogenated wrinkled shell TiO₂ architecture exhibited high efficiency in visible light oxidation of alcohols to the corresponding aldehydes (up to 90% in conversion and 97% in selectivity).