A porous carbon (PC) material, containing carbon and oxygen only, was synthesized via carbonisation of a Zn-MOF (IRMOF-8) at 950 °C. Interestingly, the derived materials of this reaction exhibit excellent electrocatalytic activity, molecular selectivity and long-term durability. The fact that this material, which is effectively a “pure” carbon, lacking any elemental doping, exhibits excellent oxygen reduction reaction (ORR) activity suggests that a mechanism not dependent on elemental doping is being utilised. We suggest the formation of defects arising from the removal of Zn atoms as a consequence of the calcination procedure play the critical role in this process.
A novel 3D metal–organic framework (MOF) with 2D rhombic channels was synthesized for selective adsorption of p-xylene from xylene isomers by acting as a molecular sieve.
With the rapid growth of nuclear power generation and fuel processing, the treatment of nuclear industry wastewater has become a major problem, and if not handled properly, it will pose a potential threat to the ecological environment and human health. Herein, a chitosan (CS)/ZIF-8 composite monolithic beads with ZIF-8 loading up to 60 wt% for U(VI) removal was prepared, which can be easily removed after use. It possesses a very high adsorption capacity of 629 mg•g−1 at pH = 3 for U(VI) and a well recyclability is demonstrated for at least four adsorption/desorption cycles. X-ray photoelectron spectroscopy (XPS) was carried out to study the adsorption mechanism between uranium and adsorbent, and the chelation of U(VI) ions with imidazole, hydroxyl, and amino groups was revealed. This work shows that CS/ZIF-8 composite can be used as an effective adsorbent for uranium extraction from aqueous solution, and has a potential application value in wastewater treatment.
21 September 2012 in Journal of Materials Chemistry
An indium trimesate metal–organic framework (JUC-120) which possesses a cubic zeolitic MTN topology, as a new analogue to MIL-100(Al, Fe or Cr) compounds, has been successfully synthesized. Its structure exhibits a mesoporous cage (26 Å) and high thermal stability. The assembly of nitrobenzospiropyran derivatives (BSP) into JUC-120 nanocrystals (BSP/JUC-120) is achieved by a microwave-assisted crystallization inclusion approach. The BSP/JUC-120 films have been prepared on quartz wafers by a spin-coating method. The successful encapsulation of BSP molecules into the mesopores of the JUC-120 structure has been verified by N2 adsorption and TGA measurements. The photochromic properties of BSP/JUC-120 films are studied by the UV-Vis and fluorescence spectroscopies. More interestingly, metastable open merocyanine (OMC) species are directly generated from the closed spiropyran form (CSP) without photoirradiation and stabilized for a long period in the BSP/JUC-120 film. The open merocyanine isomer bleaches to the closed spiropyran form by ultraviolet or visible light, and the coloration is regained upon standing in the dark, exhibiting antidromic photochromism. Moreover, the BSP/JUC-120 film shows high reversibility and thermal stability of photochromism. This highly efficient MOF film is expected to be promising in the applications of optical devices.
In this work, a series of microporous nitrogen-doped carbon catalysts are reported through a convenient preparation route, and exhibit excellent performance for oxygen reduction reaction.