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.