Recently emerged two-dimensional (2D) conductive metal-organic framework (c-MOF) thin films have brought new potential applications for various fields. This study presents a novel concept of in-situ self-assembled multifunctional semiconductor@2D-c-MOF platform (ZnInS nanosheet@ZIF-8 nanofilms, ZnInS NS@ZIF-8 NFs) for simultaneous fluorescent detection and photocatalysis. Synthesized by a facile method and subsequent in-situ self-template strategy, the obtained ZnInS NS@ZIF-8 NFs exhibits much higher photocatalytic efficiency in comparison with pristine ZnInS nanosheets and allows real-time, label-free, and sensitive fluorescent detection. In such process, the 2D ZnInS nanosheets not only serve as the semiconductor photocatalyst with large specific surface areas, but also act as self-sacrificial template to offer Zn2+ ions for the in-situ oriented growth of ZIF-8 nanofilms to achieve preconcentration and fluorescent detection for the targets. More importantly, ZIF-8 nanofilms could induce photogenerated electron transport of ZnInS. As a proof of the concept, the successful sensing and photocatalytic degradation for tetracycline have been achieved. The limit of detection is 8.6 nM in water and the photocatalytic degradation efficiency reaches 73% within 5 min under visible light, which are better than most of the previous reports. Our work could open up a new perspective for advanced photocatalyst development in the future.

A novel water-resistant and bimetallic metal organic frameworks (MOFs), Cu-ZIF-8, was successfully synthesized by a coordination synthesis method for the first time. The structure properties of obtained MOFs can be probed and confirmed with nitrogen adsorption-desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS), etc. In addition, the pore size can be convenient adjusted by doping amount of Zn(II) and Cu(II) that the body-centered cubic crystal lattice of the parent ZIF-8 framework is continuously maintained. The pseudo-second-order model can make a good description of the adsorption kinetics, while Langmuir model could well express the adsorption isotherms. The Cu-ZIF-8 exhibited a remarkable benzothiophene (BT) uptake capacity compared with those previously reported adsorbents in the literatures. Especially, the Cu-ZIF-8 displayed an outstanding stability in the presence of benzene, octane and water, maintaining more than 95% initial uptake capacity after recycling five times. The as-prepared Cu-ZIF-8 might be a hopeful material for BT capture toward deep desulfurization. Our findings explored a simple and powerful way to incorporate metal ions into the backbones of open framework materials without losing their properties.

p-Type semiconductors enable new opportunities for the development of photocatalysts. Metal-organic frameworks (MOFs) could now be manufactured for a wide range of applications. The zeolitic imidazolate framework-8 (ZIF-8), in particular, shows important desirable properties like good stability and a high surface area. Considering the p-type semiconducting intrinsic catalytic performance of CuBi2O4 (CBO) and the unique porous nanostructure and stability of ZIF-8, in this paper, we innovatively propose and investigate a new p-type semiconductor@MOFs (CBO@ZIF-8) material. Moreover, we focus on its application as a novel dual-function platform for simultaneous detection and degradation. The experimental results reveal that the platform is well suited for absorption, degradation, and fluorescent detection of certain targets. Using the contaminant, antibiotic tetracycline, as an example, the platform confirms excellent fluorescence sensing performance and good photodegradation properties under visible light. These results could aid the future design and implementation of novel and more sophisticated multifunction p-type semiconductor@MOFs platforms. The presented strategy represents the early stages of a future, genuine, general, multifunction platform.

A novel core shell magnetic composite, Fe3O4@CMC@ZIF-8-OH, was innovatively prepared using zeolitic imidazolate frameworks (ZIF-8) functionalized with carboxymethyl cellulose (CMC), Fe3O4, and phenol via wet impregnation dispersion and hydrothermal reaction techniques. Rubidium ions (Rb+ ions) can be conveniently collected from an aqueous solution due to the contribution of Fe3O4 magnetic properties. The adsorption capacity of Rb+ ions can be obviously increased because of the phenolic hydroxyl group existing on ZIF-8 with high surface area and water-resistant performance. The as synthesized novel composites were examined using N-2 adsorption-desorption, scanning electron microscopy combined with an energy-dispersive X-ray system, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, etc. The results revealed that the Fe3O4, phenol, and CMC were assembled in the ZIF-8 structure. Rb+ ions have a high adsorption rate and an extraordinary uptake capacity onto Fe3O4@CMC@ZIF-8-OH, which is preferential to the other adsorbents reported in the literature. The saturated composite was simply recovered by flushing with an ammonium nitrate solution. Even at the fifth sorption cycle, values of more than 91% adsorption efficiency were achieved for Rb+ ions. Generally, Fe3O4@CMC@ZIF-8-OH might be capable of capturing rubidium ions from water, which would be applied on a large scale if more engineering data are supported.