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This review summarizes the recent progress in preparations, functionalities and applications of composites of metal–organic frameworks (MOFs) and carbon-based materials.

In this letter, the authors directly observed the zinc-blende (ZB) ZnO core in the initial formation of wurtzite (WZ) ZnO tetrapods. The formation of the wurtzite (011¯3) twined nanowires is proposed based on the ZB core. Simple bonding density calculation shows that the wurtzite nanowires with {011¯0} side surfaces have the lowest surface energy. A favorable choice of WZ phase over ZB when forming nanostructures is likely to be a result of surface energy minimization. This could be the reason that ZnS nanowires take WZ rather than ZB.

Well-aligned single-crystalline ZnO nanobelt arrays were fabricated on a Si wafer by a carbothermal reduction route with the assistance of a SnO 2 /Sn species. The as-prepared ZnO nanobelt arrays were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, UV-vis spectroscopy, and photoluminescence spectroscopy. The photocatalytic activity for methyl orange on the ZnO nanobelt arrays was also investigated under UV irradiation. The ZnO nanobelts are several tens of nanometers in thickness, 100-500 nm in width, and have a length of up to several micrometers. It has been found that the ZnO nanobelt arrays form on a substrate only when the thickness of the SnO 2 coating is less than 100 nm. The rod-/comb-like ZnO nanostructures and the ZnO film can be obtained by increasing the SnO 2 loading or the temperature, respectively. The ZnO nanobelts grow from the active surface at the nanobelt root via a vapor-liquid-solid mechanism. The ZnO nanobelt arrays show strong emission both in the UV and in the green region. The as-prepared ZnO nanobelt arrays have a good photocatalytic property, as evidenced by the result that over 94% of the methyl orange decomposed over the ZnO nanobelt arrays, which is better than the as-prepared ZnO film and the rod-/comb-like ZnO nanostructures under identical conditions.

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This work aims to study the features of CH4 and N2 adsorption inside 1D micro-channels and develop the best suitable MOF candidates for the adsorptive separation of CH4 against N2. For this purpose, four MOFs ([Ni3(HCOO)6], [Cu(INA)2], Al-BDC and Ni-MOF-74) with similar network topology and single 1D micro-channel have been systematically investigated via structure characterization and selective gas adsorption and separation. The selected MOFs are classified into three groups. Thereinto, Ni-MOF-74, with coordinatively unsaturated metal sites, is considered as strong polar adsorbent, whilst Al-BDC is treated as moderate polar adsorbent owing to the polar linkers. However, [Ni3(HCOO)6] and [Cu(INA)2] are regarded as apolar (weak polarity) adsorbents because of lack of any polar functional groups inside the frameworks. The adsorption potential of CH4 follows the trend Ni-MOF-74 > [Ni3(HCOO)6]> [Cu(INA)2] > Al-BDC, while Ni-MOF-74 > Al-BDC > [Ni3(HCOO)6] > [Cu(INA)2] for the potential of N2. This implies that pore size and electrostatic interactions have different contributions to the CH4 or N2-MOFs interactions, resulting in excellent CH4/N2 selectivity more than 6 on [Ni3(HCOO)6] and [Cu(INA)2].

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