▎ 摘　　要

Graphene oxide (GO) and its related composites have been extensively studied for various applications due to their unique two-dimensional structure and promising performance. In this study, we reported for the first time that polyimidazole-modified GO composites (abbreviated as PILGO) could be successfully fabricated through the combination of thiol-ene click and Radziszewski reactions. Functionalized GO composites were characterized by a series of techniques, such as nuclear magnetic resonance hydrogen spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis, and the adsorption behaviour of these PILGO composites towards Congo red (CR, an anionic dye) was investigated in detail. We demonstrated that the adsorption capacity of PILGO was significantly improved as compared with that of pristine GO. The maximum uptake performance of PILGO was up to 191.9 mg g(-1) with a near-saturation state achieved in the first 5 min. The adsorption equilibrium data were better fitted through the pseudo-second-order model, while the adsorption isotherm data were better correlated with the Freundlich and Tempkin models. The adsorption affinity between CR and PILGO was positively related to the solution pH. The adsorption mechanism between CR molecules and composite material was further put forward, and it included electrostatic attraction, p-p stacking and hydrogen bond interactions. Competitive adsorption and cycling experiments further demonstrated that PILGO composites can be used as clean, efficient and novel adsorbents in wastewater treatment. (C) 2021 Elsevier B.V. All rights reserved.