Published online by Cambridge University Press: 27 June 2017
Thin films of metal-organic frameworks (MOFs) have shown promising for applications such as gas separation, gas storage, optoelectronics or sensing. However, synthesis of polycrystalline MOF films and membranes depends largely on the surface properties of supports, limiting the availability of common supports. It is, therefore, highly desirable to develop ways to modify the surface properties of common supports for the preferred heterogeneous nucleation of the MOFs. Here, we demonstrated that graphene-oxide (GO) can be exploited to readily modify the surface properties of common supports, thereby leading to well inter-grown polycrystalline MOF films. A prototypical zeolitic-imidazolate framework ZIF-8 was chosen as a model MOF system. The stabilization of GO layers with divalent metal ions was found a key step to synthesize well inter-grown ZIF-8 films. The effect of divalent metal ions on the stability of GO layers and the quality of the resulting ZIF-8 films were systematically investigated. Finally, the single gas permeation behaviors of the ZIF-8 films grown on GO-modified supports were tested.