The removal of azo dyes, which release dangerous aromatic amines by reductive cleavage, are a crucial environmental issue in the field of wastewater treatment. To achieve an effective disposal, nanocomposite hydrogels owing enhanced adsorption capacity and mechanical strength can be designed as polymeric adsorbents. In this study, novel poly(acrylamide-co-itaconic acid)/GO-polyethyleneimine (P(AAm-IA)/GO-PEI) double network nanocomposite hydrogel adsorbents were synthesized in the presence of as-prepared graphene oxide (GO) nanosheets to be used in the effective adsorption of azo dyes; cationic crystal violet (CV) and anionic direct red 23 (DR23). To determine the effect of GO amount in removing azo dyes from aqueous medium, two-dimensional graphene oxide (GO) having high amount of oxygen-containing functional groups with 1.16 nm thickness and 0.88 nm interlayer distance, was successfully prepared via the modified Hummers method. When 0.2 wt% GO was added to the polymeric network structure, the adsorption capacity increased from 390.6 to 774.46 mg g⁻¹ for CV. As well as, it was determined that the presence of PEI made the nanocomposite hydrogel sensitive for the adsorption of anionic DR 23, with an adsorption capacity of 349.29 mg g⁻¹. The adsorption capacity was found to increase with increasing GO amount, initial dye concentration, and contact time but decreased with the adsorbent amount. The adsorption is well-described by pseudo-second-order kinetics and the equilibrium data fitted well with the Langmuir isotherm model for CV and Freundlich isotherm model for DR 23 adsorption. The reausability performance of the nanocomposite hydrogels was carried out by adsorption–desorption studies and a removal efficiency of 99–84% and 75–61% for CV and DR23 was obtained after five cycles.

除去偶氮染料，其通过还原裂解释放出危险的芳族胺，是废水处理领域中至关重要的环境问题。为了实现有效的处置，可以将具有增强的吸附能力和机械强度的纳米复合水凝胶设计为聚合物吸附剂。在这项研究中，在制备的氧化石墨烯（GO）纳米片存在下，合成了新型的聚（丙烯酰胺-衣康酸）/ GO-聚乙烯亚胺（P（AAm-IA）/ GO-PEI）双网络纳米复合水凝胶吸附剂。用于有效吸附偶氮染料；阳离子结晶紫（CV）和阴离子直接红23（DR23）。为了确定GO量对从水性介质中去除偶氮染料的影响，采用二维氧化石墨烯（GO），该氧化石墨烯具有1.16 nm的厚度和0的高含量的含氧官能团。通过改进的Hummers方法成功制备了88 nm的层间距离。当将0.2 wt％的GO添加到聚合物网络结构中时，吸附容量从390.6增加到774.46 mg g对于CV为^-1。同样，确定PEI的存在使纳米复合水凝胶对阴离子DR 23的吸附敏感，吸附容量为349.29 mg g ^-1。发现吸附量随GO量，初始染料浓度和接触时间的增加而增加，但随吸附剂的量而减少。吸附通过拟二级动力学很好地描述，平衡数据与CV的Langmuir等温线模型和DR 23吸附的Freundlich等温线模型非常吻合。纳米复合水凝胶的可重整性性能通过吸附-解吸研究进行，经过五个循环后，CV和DR23的去除效率为99-84％和75-61％。