Three-dimensional graphene-assembled monoliths (GAs) are emerging materials used in supercapacitors, catalysis, etc. However, GAs prepared by mainstream reduction methods (reduced GAs, RGAs) have fewer functional groups and display poor adsorption capacity of heavy metals. In this paper, we developed a new method of preparing amide-functionalized GAs (AGAs) with high degree of modification by the reaction of carboxyl-functionalized graphene oxides and ethylenediamine. AGAs contained multiple functional groups and exhibited dendritic structure at micron scale. Benefiting from these properties, the maximum adsorption capacities Cd${}^{2+}$ on AGAs at T = 303 K were about 56.6 mg/g, which was twice that of RGAs and higher than that of graphene ($\sim$10 mg/g) and biochar ($\sim$18 mg/g) at the same conditions. By calculating the Gibbs free energies ($\Delta$G), the adsorption of Cd${}^{2+}$ on AGAs was proved a spontaneous process, while the adsorption of Cd${}^{2+}$ on RGAs was not spontaneous X-ray photoelectron spectroscopy analysis demonstrated that AGAs contained more adsorption sites and Cd${}^{2+}$ adsorbed on AGAs through coordination bond. Thus, AGAs exhibited good application potentials as adsorbents for the removal of Cd${}^{2+}$ from contaminated water.

三维石墨烯组装的整体材料（GA）是用于超级电容器，催化等的新兴材料。但是，通过主流还原方法（还原的GA，RGA）制备的GA具有较少的官能团，并且对重金属的吸附能力较差。在本文中，我们开发了一种通过羧基官能化氧化石墨烯与乙二胺的反应制备具有高度改性程度的酰胺官能化GA（AGA）的新方法。AGA包含多个官能团，并在微米级显示出树枝状结构。得益于这些特性，最大吸附容量Cd${}^{\mathrm{2个}+}$ T = 303 K时AGA的含量约为56.6 mg / g，是RGA的两倍，高于石墨烯（$〜$10毫克/克）和生物炭（$〜$18 mg / g）。通过计算吉布斯自由能（$\Delta$G），对镉的吸附${}^{\mathrm{2个}+}$ 在AGA上的吸附被证明是自发过程，而Cd的吸附${}^{\mathrm{2个}+}$ RGAs上的自发X射线光电子能谱分析表明，AGAs包含更多的吸附位点和Cd${}^{\mathrm{2个}+}$通过配位键吸附在AGA上。因此，AGAs具有良好的应用潜力，可作为吸附剂去除Cd。${}^{\mathrm{2个}+}$ 来自受污染的水。