Modified UiO-66 frameworks with methylthio, thiol and sulfonic acid function groups: The structure and visible-light-driven photocatalytic property study

Isostructural UiO-66-(SO3H)2, UiO-66-(SH)2 and UiO-66-(SCH3)2 were obtained through systemic synthesis by decorating the sulfur-containing groups (X = –SCH3, –SH, –SO3H) on the terephthalate linkers of UiO-66 (a metal-organic framework constructed with terephthalate linkers and Zr(IV)-oxo clusters). These UiO-66-X2 derivates exhibited as n-type semiconductors, wherein the electronic properties and molecule dimensions of the function groups –X played key roles in determining their band gap (Eg) and photoactive properties. The –SCH3 is shown as the most efficient functional group and is responsible for that dramatically narrowed Eg of the UiO-66-(SCH3)2 and photocatalytic property. In sharp contrast to that state-of-the-art UiO-66-NH2 (constructed with 2-aminoterephthalate linkers) having no visible-light induced photocatalytic activity to split water into H2 even with Pt as co-catalyst, Pt/UiO-66-(SCH3)2 showed a high efficient H2 generation (3871 μmol/g) from water with sacrificial ascorbic acid (0.2 M) under λ > 400 nm irradiation. The structure-property relationship of UiO-66-X2 was studied through experimental and theoretical methods.