Owing to its low-cost, eco-friendly and multiple oxidation states, the ternary transition metal oxide CuCo2O4 has been used as an electrode material with superior electrocatalytic activity in numerous fields, whereas...

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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,) and Co(NO 3 ) 2 •6H 2 O as starting materials in a hydrothermal reaction via a decomposition−reassembly route together with the rational adjustment of pH values. Co 9 W 10 has been structurally characterized using single-crystal X-ray diffraction. Photocurrent response, band-gap (E g ) value, and the VB-XPS spectrum have been measured to reveal the semiconducting property of Co 9 W 10 . Furthermore, we synthesized x% PTh/Co 9 W 10 composites (PTh = polythiophene, x = 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/Co 9 W 10 composites show the best photocatalytic activities among these composites.

Photocatalytic nitrogen fixation has attracted much attention due to the fact that it is a way of using solar energy to achieve clean and sustainable conversion of nitrogen to ammonia under mild conditions. In this paper, different proportions of Zn-doped Co 3 O 4 nanopolyhedrons were synthesized using bimetallic ZIFs containing Co 2+ and Zn 2+ as precursors for the construction of photocatalytic nitrogen fixation semiconductor materials for the first time. The synthesized Co 3 O 4 nanopolyhedron still retains the rhombic dodecahedron shape of ZIF-67 and exhibits a large specific surface area. Moreover, Zn doping results in abundant oxygen vacancies on the surface of Co 3 O 4 polyhedron. These oxygen vacancies not only provide active sites for nitrogen adsorption and activation, but also enhance the separation ability of photocarriers, which can significantly improve the efficiency of photocatalytic nitrogen fixation of the material. When Zn-Co 3 O 4 -30 is utilized as the catalyst for photocatalytic nitrogen fixation, the nitrogen fixation rate is 96.8 μmol g −1 h −1 , which is much higher than that of pure-Co 3 O 4 . In this study, heteroatom-doped Co 3 O 4 polyhedron with rich oxygen vacancy was synthesized by low-temperature oxidation method, which provides a new idea for the design and synthesis of skeleton-based photocatalytic nitrogen fixation materials.

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