A Calix[4]resorcinarene-Copper(II) Based Supramolecular Nanocapsule with Encapsulated Polyoxometalates for Enhanced Photocatalytic Activity

The research on improving the photocatalytic activity of polyoxometalates (POMs) has attracted considerable attention. In this work, a functionalized calix[4]resorcinarene ligand with four terpyridine groups (TPYR4A) was rationally designed, and then a POM-calix[4]resorcinarene based inorganic–organic complex [Cu 4 Cl 4 (TPYR4A)] 2 [PW VI 10 W V 2 O 40 ][PW VI 12 O 40 ]·6DMA·8H 2 O (DMA= N, N ′-dimethylacetamide) ( 1 ) was achieved by a self-assembly process. Strikingly, POM clusters were successfully encapsulated in noncovalent dimeric calix[4]resorcinarene-copper(II) based nanocapsules with a size of 3 nm. Markedly, 1 features a visible light absorption response with an optical band gap of 2.3 eV. More importantly, 1 exhibits obviously enhanced photocatalytic activity for oxidation of benzaldehyde upon simulated solar light excitation. Particularly, the photocatalytic performance of 1 is better than that of pure H 3 PW 12 O 40 or a mixture of TPYR4A and H 3 PW 12 O 40 . This work offers a feasible strategy for designing POM-based hybrid materials with enhanced photocatalytic activity.