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

Engineered graphene highly wrapped yolk@shell TiO2 (G-HW-Y@S-TiO2) architectures were synthesized from fundamental understanding using a multi-step approach as advanced photocatalytic nanomaterials. The resultant G-HW-Y@S-TiO2 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-TiO2 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. © 2018