Spatial separation of redox centers for boosting cooperative photocatalytic hydrogen evolution with oxidation coupling of benzylamine over Pt@UiO-66-NH₂@ZnIn₂S₄

The construction of an overall photocatalytic redox system through the combination of photocatalytic hydrogen evolution (PHE) with the oxidative coupling of benzylamine into imines is highly desirable. Herein, a yolk-shell heterojunction Pt@UiO-66-NH2@ZnIn2S4 (Pt@UiO-66-NH2@ZIS) is synthesized and successfully utilized as a dual-functional photocatalyst for C-N coupling reaction of benzylamine and proton reduction half-reaction. In this dual-catalytic system, the hole collector ZnIn2S4 can trap and release the holes of UiO-66-NH2 to accelerate the C-N coupling reaction, while the electron collector Pt acts as an electron collector and an active site for the reduction of protons to H-2. As expected, Pt@UiO-66-NH2@ZIS shows 4 and 16 times higher catalytic activities than that of individual ZnIn2S4 and UiO-66-NH2, respectively. Consequently, the optimal photocatalyst simultaneously promotes C-N coupling reaction (78%) and H-2 evolution (850 mu mol g(-1) h(-1)). This unique design offers great prospects for other highly efficient synergistic dual-functional photocatalytic systems.