Engineered bi-functional hydrophilic/hydrophobic yolk@shell architectures: A rational strategy for non-time dependent ultra selective photocatalytic oxidation.

Graphical abstract Highlights • Design of graphene highly wrapped yolk@shell TiO 2 nanostructures. • Engeenering bi-functional hydrophilic/hydrophobic yolk@shell architectures. • Unusual non-time dependent ultra selective alcohol oxidation under visible light. Abstract Engineered graphene highly wrapped yolk@shell TiO 2 (G-HW-Y@S-TiO 2) architectures were synthesized from fundamental understanding using a multi-step approach as advanced photocatalytic nanomaterials. The resultant G-HW-Y@S-TiO 2 architecture exhibited a superior selective photocatalytic performance in visible light oxidation of aromatic alcohols to corresponding aldehydes (up to 99% in 4 h reaction). Interestingly, the aldehyde was still obtained as single oxidation product after 12 h in presence of G-HW-Y@S-TiO 2 structure. The observed non-time dependent photocatalytic oxidation selectivity can be attributed to the engineered photocatalyst architecture with different hydrophilic level sites between inner core and outer shell that force the hydrophobic aldehyde products to diffuse out from the hydrophilic void space preventing further over-oxidation. [ABSTRACT FROM AUTHOR]