Herein, we studied the adsorption behaviors of organic micropollutants, such as anticonvulsant carbamazepine (CBZ) and antibiotic tetracycline hydrochloride (TC), on zirconium metal-organic framework UiO-66 in water. The maximum adsorption capacities of CBZ and TC on the UiO-66 were 37.2 and 23.1 mg·g at 25 °C, respectively. The adsorption isotherms and kinetics of CBZ and TC were well described by using the Langmuir model and pseudo-second-order model, respectively, and the adsorptions on UiO-66 are endothermic reactions. The adsorption capacities of CBZ and TC on UiO-66 were decreased with the increase of solution pH. The presence of humic acid could improve the adsorption of CBZ and TC on UiO-66, but K ion inhibited their adsorption obviously. In addition, Ca and Al ions also suppressed the adsorption of TC on UiO-66. The competitive adsorption suggested that the adsorption sites for CBZ on UiO-66 were different from those for TC. The surface interactions between UiO-66 and the two micropollutants were demonstrated by powder X-ray diffraction, Fourier transform infrared (FT-IR) spectra, scanning electron microscopy, nitrogen adsorption/desorption isotherms, and X-ray photoelectron (XPS) spectra. The characterizations showed that the adsorption of CBZ on UiO-66 is mainly a physisorption, and the hydrophobic effect played a crucial role during the adsorption of CBZ; meanwhile weak π-π electron donor-acceptor interaction and electrostatic attraction also existed. However, the adsorption of TC on UiO-66 is mainly a chemisorption; in addition to the strong electrostatic attraction and π-π electron donor-acceptor interaction forces, the nitrogenous groups of TC played an important role, which can replace the carboxylic groups coordinated with Zr-O clusters. The obtained results will aid us to comprehend the surface interaction between organic micropollutants and UiO-66 and expand the application of UiO-66 as sorbent for removal of pollutants from water.

No abstract

Novel α‐MnS hollow spheres (MHSs) have been fabricated successfully by a one‐pot template‐free solvothermal method. The as‐synthesized α‐MnS spheres have diameters of about 3–5 μm and porous shells of thickness about 0.5 μm composed of numerous nanocrystals. The samples were characterized by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption. Time‐dependent morphology evolution suggested that transformation of chemical components and Ostwald ripening play vital roles for these hollow structures with a porous shell. The possible formation mechanism for the fabrication of MHSs is proposed. Meanwhile, MHS–reduced graphene oxide (RGO) hybrids have been prepared in the presence of graphene oxide (GO) by using the same procedure. The amount of GO can affect the morphology of α‐MnS crystals in hybrids. The microwave absorption and lithium storage properties of the pure MHSs and MHS–RGO hybrids were studied in detail. Compared with pristine MHSs, the MHS–RGO hybrids possess remarkably enhanced microwave absorption and lithium storage properties. The enhanced microwave absorbing and electrochemical properties are also explained.

No abstract

As promising electrode materials in supercapacitors, metal–organic frameworks (MOFs) have attracted significant attention. However, the poor electrical conductivity and the almost exclusively microporous structure largely limited the possibility for MOFs to fabricate high-performance electrodes of supercapacitors. To overcome these obstacles, hierarchical porous Zr-MOFs (HP-UiO-66) has been successfully fabricated using bimetallic Zn/Zr MOFs as a precursor, subsequently wiping off Zr-MOFs. When used as electrode materials for supercapacitors, under a current density of 0.2 A g–1, the specific capacitance of the prepared HP-UiO-66 is 849 F g–1, which is 8.36 times higher than the 101.5 F g–1 of bare UiO-66. The clearly enhanced electrochemical performance of HP-UiO-66 was benefited from the advantages of the hierarchical porous structure, the higher specific surface area and pore volume, as well as the sufficient surface defects. Furthermore, an aqueous asymmetric supercapacitor based on the HP-UiO-66 and porous carbon could show an energy density of 32 W h kg–1 at a power density of 240 W kg–1. This strategy may offer a versatile idea of tailoring new type of MOFs and opens the possibility of MOFs using in the future high-energy storage device.

No abstract

Magnetic Fe–Cx as heterogeneous Fenton-like catalysts were synthesized by the pyrolysis of Fe-MOF, and the catalytic activity of Fe–Cx for removal of 4-NP was significantly affected by pyrolysis temperature.

No abstract