Pt Nanoparticles@Photoactive Metal–Organic Frameworks: Efficient Hydrogen Evolution via Synergistic Photoexcitation and Electron Injection

Pt nanoparticles of 2–3 nm and 5–6 nm in diameter were loaded into stable, porous, and phosphorescent metal–organic frameworks (MOFs 1 and 2) built from [Ir­(ppy)2(bpy)]+-derived dicarboxylate ligands (L1 and L2) and Zr6(μ3-O)4(μ3-OH)4(carboxylate)12 secondary building units, via MOF-mediated photoreduction of K2PtCl4. The resulting Pt@MOF assemblies serve as effective photocatalysts for hydrogen evolution by synergistic photoexcitation of the MOF frameworks and electron injection into the Pt nanoparticles. Pt@2 gave a turnover number of 7000, approximately five times the value afforded by the homogeneous control, and could be readily recycled and reused.