Graphene oxide: A promising nanomaterial for energy and environmental applications

Metal–organic frameworks (MOFs), assembled by metal ions or their clusters and organic linkers, are one of the state-of-the-art crystalline materials. Their features such as ultra-high porosity, synthetic tailorability and relative ease of synthesis make them promising candidates for diversified applications. Controllable integration of MOFs and carbon-based materials not only leads to further enhancement of single-phase MOFs in terms of stability and electrical conductivity, but also surprisingly brings about a number of new functionalities like formation of new pores and template effects. These benefits allow the resultant MOF–carbon composites to be applied beyond the fields of single-phase MOFs. Increasing research interests have been aroused in this rapidly developing interdisciplinary area. This review aims to specifically group together the important reports focused on MOF–carbon composites till now. The methods used for composite synthesis and applications of the composites are investigated and categorized. The review also exclusively discusses the functionalities stemming from the synergistic effects of the two intriguing materials and pictures the future prospects at the end.

Composites of metal–organic frameworks and carbon-based materials: preparations, functionalities and applications

In this work, MIL-53(Fe)-reduced graphene oxide (M53-RGO) nanocomposites have been successfully fabricated by a facile and efficient electrostatic self-assembly strategy for improving the interfacial contact between RGO and the MIL-53(Fe). Compared with D-M53-RGO (direct synthesis of MIL-53(Fe)-reduced graphene oxide nanocomposites via one-pot solvothermal approach), M53-RGO nanocomposites exhibit improved photocatalytic activity compared with the D-M53-RGO under identical experimental conditions. After 80 min of visible light illumination (λ ≥ 420 nm), the reduction ratio of Cr(VI) is rapidly increased to 100%, which is also higher than that of reference sample (N-doped TiO2). More significantly, the M53-RGO nanocomposites are proven to perform as bifunctional photocatalysts with considerable activity in the mixed systems (Cr(VI)/dyes) under visible light, which made it a potential candidate for industrial wastewater treatment. Combining with photoelectrochemical analyses, it could be revealed that the i...

Preparation of MIL-53(Fe)-Reduced Graphene Oxide Nanocomposites by a Simple Self-Assembly Strategy for Increasing Interfacial Contact: Efficient Visible-Light Photocatalysts

Metal-Organic Frameworks/Graphene-Based Materials: Preparations and Applications

It is still a great challenge to develop efficient semiconductive photocatalysts responding to visible light radiation. We show an efficient ZnIn2S4/UiO-66 hybrid photocatalysts with flowerlike 3D microspheres synthesized via a facile solvothermal method. A 20 wt.% UiO-66 emersion raises the Cr(VI) reduction rate up to 99% and higher after 60 min visible light irradiation. The substantial enhancement of photocatalytic and photoelectronchemical activity of pure ZnIn2S4 by UiO-66 addition is attributed to the ZnIn2S4/UiO-66 interfacial charge transferring and more active sites for pollute adsorption.

Efficient charge separation between UiO-66 and ZnIn2S4 flowerlike 3D microspheres for photoelectronchemical properties

Enhanced room-temperature hydrogen storage capacity in Pt-loaded graphene oxide/HKUST-1 composites

Composites of the Cr3+-based metal-organic framework (MIL-101) and graphene oxide (GO) have been synthesized with different ratios of MIL-101 and GO. The composites and the parent material MIL-101 were characterized by X-ray diffraction, scanning electron microscopy and nitrogen adsorption. The results indicated that the incorporation of large amounts of GO (10 and 20 wt%) almost did not prevent the formation of MIL-101 units, but had an obvious impact on the size of MIL-101 crystals. On the contrary, small amounts of GO added (2 and 5 wt%) prevented significantly the proper assembly of MIL-101 units, thus resulting in a pronounced decrease in the porosities of composites.

Syntheses, Characterizations and Adsorption Properties of MIL‐101/Graphene Oxide Composites

Nanocomposites of Pt-doped graphene oxide (GO) and a chromate–organic framework (MIL-101) were prepared through the in situ solvent-thermal method. The parent materials and all composites have been characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, and gas adsorption analysis. The results indicated that the incorporation of a Pt/GO component did not prevent the formation of MIL-101 units. However, the crystallinities, morphologies, and surface areas of the composites were affected obviously by the Pt/GO content. The significant enhancement by a factor of 1.57–2.69 of hydrogen storage capacities at ambient temperature and 10 bar for the composites can be attributed reasonably to the spillover mechanism in such a system, in which Pt nanoparticles act as the spillover source of hydrogen molecules, while GO and MIL-101 act as the primary and secondary receptors, respectively.

Xiaoqing Liu

Papers

Enhanced room-temperature hydrogen storage capacity in Pt-loaded graphene oxide/HKUST-1 composites

Syntheses, Characterizations and Adsorption Properties of MIL‐101/Graphene Oxide Composites

Pt-doped graphene oxide/MIL-101 nanocomposites exhibiting enhanced hydrogen uptake at ambient temperature

Two Zn(II) and Co(II) compounds with dicarboxylates and curved 4,4′-azopyridine ligands: Syntheses, crystal structures and gas sorption properties

Syntheses, structures, thermal stabilities and gas sorption properties of two rod-based microporous lead(II) polycarboxylate coordination frameworks