Tailored synthesis of mesoporous TiO2 hollow nanostructures for catalytic applications

Nanostructured TiO2 has attracted significant attention due to its advantageous properties for practical catalytic applications. TiO2 hollow nanostructures consisting of nanoscale porous shells are highly desirable because they possess high active surface area, reduced diffusion resistance, and improved accessibility, which provide many new opportunities to the design of highly active nanostructured catalysts. Although much has been explored, tailored synthesis of TiO2-based hollow nanostructures towards practical catalytic applications has been very limited. In this article, we first introduce the general synthetic strategies for preparing TiO2 hollow nanostructures, and then focus our discussion on the novel synthetic strategies developed in our group with emphasis on controlling the crystallinity as well as physical characteristics of TiO2 hollow nanostructures. We further discuss several catalytic applications of TiO2-based hollow shells and metal@TiO2 yolk–shell nanostructures for photocatalytic dye degradation, H2 production and gas-phase CO oxidation. Finally, we conclude with our personal perspective on the future research efforts for addressing several remaining challenges in the design of TiO2-based catalysts.