Integration of chromium terephthalate metal-organic frameworks with reduced graphene oxide for voltammetry of 4-nonylphenol

Metal-organic frameworks (MOFs) are attractive materials for electrochemical applications because of their large surface areas and rich pore structures. However, their poor electrical conductivity hinders these applications. In this contribution, the decoration of chromium terephthalate MOFs (MIL-101(Cr) crystals) with reduced graphene oxide (rGO) is proposed to improve the electrical conductivity of MIL101(Cr) crystals. These nanocomposites (MIL-101(Cr)@rGO) were prepared using a simple chemical reduction method. Their morphology, interfacial properties, and electrochemical applications were investigated using electron microscopy, electrochemical, and related techniques. With an introduction of rGO into MIL-101(Cr) crystals, the conductivity of MIL-101(Cr)@rGO nanocomposites was much improved. As a case study of electrochemical applications of MIL-101(Cr)@rGO nanocomposites, the MIL101( Cr)@rGO nanocomposite coated electrodes were employed for the voltammetric study of 4-nonylphenol. An irreversible, adsorption-controlled, one electron and one proton involved oxidation process was observed. By use of the recorded anodic peak current as the physical parameter, the sensitive and reproducible monitoring of 4-nonylphenol was realized in the range of 0.1-12.5 mu M with a detection limit of 33 nM. The MIL-101(Cr)@rGO nanocomposites are thus useful electrode materials. The proposed strategy provides a simple and efficient approach to expand easily the applications of MOFs into various electrochemical fields. (C) 2018 Elsevier Ltd. All rights reserved.