Decomposition-Reassembly Synthesis of a Silverton-Type Polyoxometalate 3D Framework: Semiconducting Properties and Photocatalytic Applications.

Polyoxometalate-based all-inorganic three-dimensional (3D) frameworks have recently attracted attention as a unique class of materials due to their unique physicochemical properties and a wide field of application with excellent prospects. We herein synthesized a novel all-inorganic 3D framework material based on cobalt-substituted Silverton-type polyoxometalate, H{CoWO[Co(HO)]}·2HO (CoW), which was successfully constructed using Na[WCo(HO)(CoWO)]·46-48HO (CoW) and Co(NO)·6HO as starting materials in a hydrothermal reaction via a decomposition-reassembly route together with the rational adjustment of pH values. CoW has been structurally characterized using single-crystal X-ray diffraction. Photocurrent response, band-gap () value, and the VB-XPS spectrum have been measured to reveal the semiconducting property of CoW. Furthermore, we synthesized % PTh/CoW composites (PTh = polythiophene, = 0.5, 1, 2, 5) for photodegradation of tetracycline hydrochloride (TH) to evaluate the photocatalytic activities of title composites. Due to the optimal molar ratio of hybrids and matching energy levels, 2% PTh/CoW composites show the best photocatalytic activities among these composites.