In situ synthesis of ordered mesoporous Co-doped TiO2 and its enhanced photocatalytic activity and selectivity for the reduction of CO2

Abstract

Ordered mesoporous cobalt-doped titanium dioxide was successfully synthesized by a multicomponent self-assembly process. The doped Co species change the construction of the conduction band and valence band of TiO₂, leading to visible-light absorption for TiO₂. The designed cobalt-doped titanium dioxide exhibits a higher visible light activity for the reduction of CO₂ among the commonly reported photocatalysts. In addition, the selectivity of the reduction products is improved by optimizing the energy-band configurations of cobalt-doped titanium dioxide through varying the molar ratio of Co/Ti. When the doping content of cobalt species increases to some extent, Co₃O₄/Co-doped TiO₂ nanocomposites with oxygen vacancies were obtained, which markedly improve the generation rate of CH₄.