N-K2Ti4O9/UiO-66 composites synthesized by a facile solvothermal method possess a hierarchical core–shell structure with UiO-66 forming the shell around the N-K2Ti4O9 core. Photocatalytic activity of N-K2Ti4O9, UiO-66 and the composites were investigated by the degradation of rhodamine B (RhB) under visible light irradiation. The synergistic effect induced by compounding was quantitatively evaluated by the proposed synergistic factor. The results show that N-K2Ti4O9/UiO-66 composites exhibit higher photocatalytic activity as compared with the pure materials, and this is due to the high adsorption capacity of UiO-66 and the compounding induced higher separation efficiency of photogenerated electron–hole pairs. In particular, when the molar ratio of N-K2Ti4O9 to ZrCl4 is 3:7, the composite exhibits the highest photocatalytic activity, and the synergistic factor is 4.90.

In this study, a novel composite containing a Cr based metal–organic framework (MOF), MIL-101 and BiVO4 was successfully synthesized by hydrothermal method, and was fully characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, UV-vis diffuse reflectance absorption spectra and photoluminescence emission spectra. Moreover, the photocatalytic activities of BiVO4/MIL-101 composite and the pure materials were evaluated by measuring the degradation of Rhodamine B under visible light. The results show that the composite exhibits better photocatalytic activities than pure materials, which can be ascribed to the big adsorption capacity of MIL-101 and the enhanced separation of photogenerated charge carriers from assembly of MIL-101 on BiVO4. The synergistic effect between BiVO4 and MIL-101 was evaluated by the proposed synergistic factor, which is bigger than 1 for various ratios of BiVO4 to MIL-101, suggesting there exists positive interactions between pure materials for enhancing photocatalytic activities.

N-K2Ti4O9/MIL-101 composites were successfully synthesized by a facile hydrothermal method, and were characterized by powder X-ray diffraction, UV–vis diffuse reflectance spectroscopy, the valence band X-ray photoelectron spectroscopy, field emission transmission electron microscopy, photoluminescence emission spectra, N2 adsorption–desorption and thermogravimetric analysis. Photocatalytic activities of N-K2Ti4O9, MIL-101 and the composites were investigated by the degradation of Rhodamine B (RhB) under visible light irradiation. The results show that the composites exhibit higher photocatalytic activity as compared with the pure materials. The synergistically enhanced photocatalytic activity of the composites is due to big adsorption capacity of MIL-101 and high separation efficiency of photogenerated electron-hole pairs through interfaces between N-K2Ti4O9 and MIL-101.

A new double μ-1,3-azido-bridged binuclear Ni(II) complex 1 ([Ni2(L)2(μ-N3)2](ClO4)2 (L = [N,N′,N″-tris(4-methoxylbenzyl)tris(2-aminoethyl)amine]) was synthesized and characterized by X-ray crystallography and magnetic measurements. In 1, two N3- ligands bridge two Ni(II) ions with the μ-1,3 mode and cross each other to give a rarely observed non-coplanar (N3)2 structure. The unique ferromagnetic coupling mediated by double μ-1,3-azido bridges mainly attributes to the Ni–N–N–N–Ni torsion angles being approaching 90°.

The adsorption characteristics of UiO-66 (a Zr-containing metal–organic framework formed by terephthalate) for Rhodamine B (RhB), such as isotherms, kinetics and thermodynamics, were investigated systematically. The batch adsorption data conform well to the Langmuir and Freundlich isotherms. The adsorption kinetics of UiO-66 for RhB can be well described by the pseudo first-order model, and the adsorption thermodynamic parameters ΔG0, ΔH0 and ΔS0 at 273 K are − 6.282 kJ·mol− 1, 15.096 kJ·mol− 1 and 78.052 J·mol− 1·K− 1, respectively. The thermodynamic analyses show that the adsorption process of RhB on UiO-66 is more favorable at higher temperatures. UiO-66 can be regenerated by desorbing in DMF solution with ultrasonic for 1 h. UiO-66 can keep good performance for at least six cycles of sorption/desorption.The adsorption characteristics of UiO-66 for Rhodamine B (RhB), such as the isotherms, kinetics and thermodynamics, were investigated. The results show that the adsorption process is more favorable at higher temperatures. UiO-66 can be regenerated by desorbing in DMF solution with ultrasonic for 1 h, and keep good performance for sorption/desorption after at least six cycles.Download full-size image

In the present study, MIL-101(Cr) and Bi25FeO40 were successfully synthesized by hydrothermal method, and were wrapped by polythiophene (PTH) to form a new composite catalyst, Bi25FeO40/MIL-101/PTH. The pure materials and composite were fully characterized by X-ray diffraction, transmission electron microscopy and UV–vis spectrophotometer. Moreover, the photocatalytic activities of the catalysts were evaluated by measuring the degradation of Rhodamine B under visible light. The results show that the composites exhibit better photocatalytic activities than pure materials and P25, which can be ascribed to the big adsorption capacity of MIL-101(Cr) and the rapid transferring and separation of photogenerated charge carriers through PTH connected interface between MIL-101(Cr) and Bi25FeO40.