A High‐Symmetrical 3D Pure Inorganic Photocatalyst Based on the Highest Connectivity of {AsW12O40} Heteropoly Blue and Potassium Ions

A 3D high‐symmetrical pure inorganic material based on a Keggin‐type arsenotungstate, [{(H2O)⊂K6(H2O)12}{K6(AsW3VW9VIO40)2}] (1), has been hydrothermally synthesized and fully characterized by elemental analysis, TGA, IR, UV, and XPS spectrsocopy, and single‐crystal XRD. In compound 1, each three‐electron‐reduced {AsW12O40} polyanion cluster utilizes all of its surface oxygen atoms to connect 12 K1 and 6 K2 cations at its periphery, which can be viewed as µ4‐ and µ2‐bridges to further link with four and two adjacent {AsW12} clusters, respectively. The coordination number and modes of {AsW12} and K+ ions together result in a high‐symmetrical 2,4,18‐connected 3D open skeleton with a new {324·440·54·43·54·42·54·42·54·4·532·633}{34·42}3{3}3 topology. Compound 1 represents the first pure inorganic 3D structure based on the highest connection of Keggin arsenotungstate heteropoly blue and potassium ions. Compound 1 shows efficient photodegradation activity towards MB, MO, RhB, and AP under UV light irradiation. The life of the catalyst, kinetics, and mechanisms of the catalytic reaction have been studied in detail. A K+ cation as linkage unit has been introduced into the {AsW12} reaction system to build a high‐symmetrical pure inorganic 3D extended framework with a complex topology, which represents the highest‐connected Keggin arsenotungstate heteropoly blue and shows excellent photocatalytic activities for the degradation of typical dyes.