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 al-dehydes (up to 99% in 4 h reaction). Interestingly, the al-dehyde was still obtained as single oxidation product after 12h 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 al-dehyde products to diffuse out from the hydrophilic void space preventing further over-oxidation.