A Green<i> In Situ</i> Synthesis of Hybrid Graphene-Based Zeolitic Imidazolate Framework-8 Nanofillers Using Recycling Mother Liquor

Abstract

In this study, two types of hybrid graphene-based zeolitic imidazolate framework-8 (ZIF-8) nanofillers were prepared via a green in-situ synthesis method. A recycle mother liquor (ML) of ZIF-8 which still contains expensive raw materials used for the synthesis of ZIF-8 such as Zn2+, Hmim and methanol was reutilized for the synthesis of graphene oxide-ZIF-8 (GO-ZIF-8-ML) and reduced graphene oxide-ZIF-8 (rGO-ZIF-8-ML) to minimize chemicals wastage. The as-synthesized GO-ZIF-8 and rGO-ZIF-8 fillers were then characterized by using fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffractometer (XRD) and thermogravimetric analyser (TGA) and compared with the pure components such as GO, rGO and ZIF-8. No significant changes in the chemical structures of GO-ZIF-8 and rGO-ZIF-8 and the XRD peaks were found to match well with ZIF-8. This indicates that during the in-situ process, both GO and rGO, which serve as a template for anchoring of ZIF-8 do not affect the formation of ZIF-8 and the hybrid nanofillers synthesized were homogenized. TGA results revealed that the as-synthesized GO-ZIF-8-ML and rGO-ZIF-8-ML have better structural stability. The morphology observed from SEM analysis demonstrated that the synthesized ZIF-8 was successfully anchored on the surface of GO and rGO. The hybrid nanofillers showed better properties as compared to pure components.