This study describes a novel adsorbent with a multidentate ligand that was facilely fabricated by covalently bonding 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole on graphene oxide (AHMT-PRGO). The AHMT-PRGO nano-adsorbent was used for the effective removal of Hg(II), Pb(II), and Cr(VI) from wastewater. The AHMT-PRGO nano-adsorbent was synthesized by a nucleophilic substitution reaction between GO acyl chloride and AHMT chelating ligand in the presence of tetrabutyl-ammonium bromide as a catalyst. The successful modifications were confirmed via several spectroscopic and electron microscopy instrumentations including UV–Vis, FTIR, Raman, XRD, XPS, SEM, and TEM. The maximum adsorption capacities of Hg(II), Cr(VI), and Pb(II) on the AHMT-PRGO nano-adsorbent were 370.0, 136.2, and 109.6 mg/g, respectively, exceeding those of most previously reported adsorbents. Additionally, the equilibrium contact times for Hg(II), Pb(II), and Cr(VI) were 60, 30, and 400 min, respectively. In a mixture of nine heavy metal ions containing 250 ppm of each ion, the AHMT-PRGO nano-adsorbent exhibited high selectivity for Hg(II) ions. Furthermore, the AHMT-PRGO nano-adsorbent showed high stability over five adsorption–desorption cycles. Additionally, the AHMT-PRGO nano-adsorbent was successfully applied to remove heavy metal ions from real water samples. The novelty of AHMT-PRGO lies in the combination of a multidentate ligand for strong and selective binding with the high surface area and stability offered by covalently bonded graphene oxide. This combination offers potential advantages over traditional adsorbents in terms of adsorption capacity, selectivity, and reusability.

本研究描述了一种具有多齿配体的新型吸附剂，该吸附剂是通过将 4-氨基-3-肼基-5-巯基-1,2,4-三唑共价键合在氧化石墨烯 (AHMT-PRGO) 上而轻松制备的。 AHMT-PRGO纳米吸附剂用于有效去除废水中的Hg(II)、Pb(II)和Cr(VI)。以四丁基溴化铵为催化剂，GO酰氯与AHMT螯合配体发生亲核取代反应，合成了AHMT-PRGO纳米吸附剂。通过多种光谱和电子显微镜仪器（包括 UV-Vis、FTIR、拉曼、XRD、XPS、SEM 和 TEM）证实了修饰的成功。 AHMT-PRGO 纳米吸附剂对 Hg(II)、Cr(VI) 和 Pb(II) 的最大吸附容量分别为 370.0、136.2 和 109.6 mg/g，超过了大多数先前报道的吸附剂。此外，Hg(II)、Pb(II) 和 Cr(VI) 的平衡接触时间分别为 60、30 和 400 分钟。在每种离子含量为 250 ppm 的九种重金属离子的混合物中，AHMT-PRGO 纳米吸附剂对 Hg(II) 离子表现出高选择性。此外，AHMT-PRGO纳米吸附剂在五个吸附-解吸循环中表现出高稳定性。此外，AHMT-PRGO纳米吸附剂还成功应用于去除真实水样中的重金属离子。 AHMT-PRGO 的新颖性在于将多齿配体与共价键合氧化石墨烯提供的高表面积和稳定性进行强选择性结合。这种组合在吸附能力、选择性和可重复使用性方面比传统吸附剂具有潜在优势。