Polyoxometalate-Based Metal–Organic Frameworks\nas Visible-Light-Induced Photocatalysts

Abstract

Two stable 3D polyoxometalate-based\nmetal–organic frameworks (PMOFs), [Cu^I₁₂(trz)₈(H₂O)₂]­[α-SiW₁₂O₄₀]·2H₂O (<b>1</b>) and [Cu^I₁₂(trz)₈Cl]­[α-PW₁₂O₄₀] (<b>2</b>) (Htrz = 1-<i>H</i>-1,2,4-triazole)\nbased on Keggin-type POMs were successfully obtained and fully characterized.\nThe basic building units of the two PMOFs are [Cu^I₁₂(trz)₈], but polyoxoanion (POA) template effect\nleads to different structures and properties: <b>1</b> represents\nan interesting example that [α-SiW₁₂O₄₀]^4– locate in the nine-membered Cu-trz rings through\nCu···O weak interactions to form a 3D framework, whereas <b>2</b> shows a 3D structure constructed from 2D bilayer cationic\nnetwork [Cu^I₁₂(trz)₈Cl]³⁺ and [α-PW₁₂O₄₀]^3– lying\nin the adjacent layers via Cu···O weak interactions.\nPMOF <b>1</b> as unusual visible-light photocatalyst exhibit\nsignificantly enhanced photocatalytic activity under visible-light\nand excellent stability during the photocatalysis process for recovering\nand recycling, as well as photocatalytic hydrogen evolution activity.