Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, United States; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, United States.
Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, United States.
Sci Total Environ. 2020 Oct 10;738:139213. doi: 10.1016/j.scitotenv.2020.139213. Epub 2020 May 12.
A series of highly efficient adsorbents were developed using Ni(BTC) and Co(BTC) metal-organic frameworks (MOFs) and FeO magnetic nanoparticles (MNPs) to functionalize graphene oxide (GO). XRD results show high crystallinity of the prepared nanomaterials and the successful decoration of Ni(BTC) and Co(BTC) MOFs over the GO substrate (BTC = benzene-1,3,5-tricarboxylic acid). SEM and TEM imaging show the successful formation of nanoscale MOFs and FeO MNPs over GO. IR spectroscopy supports the characterization and successful preparation of the FeO/MOF@GO hybrid composite nanoadsorbents. The prepared composite nanoadsorbents were used to sorb Methylene Blue (MB) as a model for common organic pollutants in water and common ions (Na, Ca, Mg, SO, SiO) from a brackish water model. The adsorbed concentration at equilibrium of MB of the prepared composite nanoadsorbents increases by an average of 30.52 and 13.75 mg/g for the Co and Ni composite, respectively, when compared to the MOFs parent materials. The adsorbed amount of sulfate ions increases by 92.1 mg/g for the Co composite and 112.1 mg/g for the Ni composite, when compared to graphene oxide. This adsorption enhancement is attributed to suppressed aggregation through increased dispersive forces in the MOFs due to the presence of GO, formation of nanoscale MOFs over the GO platform, and the hindering of stacking of the graphene layers by the MOFs. Leaching tests show that the release of Co and Ni ions to water is reduced from 105.2 and 220 mg/L, respectively, in the parent MOF materials to 0.5 and 16.4 mg/L, respectively, in the composite nanoadsorbents. These findings show that the newly developed composite nanoadsorbents can sorb organic pollutants, and target sulfate and silicate anions, which makes them suitable candidates for water and wastewater treatments.
一系列高效的吸附剂是通过 Ni(BTC) 和 Co(BTC) 金属有机骨架(MOFs) 和 FeO 磁性纳米粒子(MNPs) 来功能化氧化石墨烯(GO)而开发的。XRD 结果表明，所制备的纳米材料具有高结晶度，并且成功地在 GO 基底上装饰了 Ni(BTC) 和 Co(BTC) MOFs(BTC=苯-1,3,5-三羧酸)。SEM 和 TEM 成像表明，成功地在 GO 上形成了纳米级 MOFs 和 FeO MNPs。IR 光谱支持 FeO/MOF@GO 杂化复合纳米吸附剂的表征和成功制备。所制备的复合纳米吸附剂用于吸附亚甲基蓝(MB)作为水中常见有机污染物和咸水模型中常见离子(Na、Ca、Mg、SO4、SiO)的模型。与 MOFs 母体材料相比，制备的复合纳米吸附剂对 MB 的平衡吸附浓度分别增加了 30.52 和 13.75 mg/g，用于 Co 和 Ni 复合材料。与氧化石墨烯相比，Co 复合材料的硫酸根离子吸附量增加了 92.1 mg/g，Ni 复合材料的硫酸根离子吸附量增加了 112.1 mg/g。这种吸附增强归因于 GO 的存在抑制了 MOFs 的团聚，增加了分散力，在 GO 平台上形成了纳米级 MOFs，以及 MOFs 阻碍了石墨烯层的堆积。浸出试验表明，Co 和 Ni 离子从母体 MOF 材料中分别向水中的释放量从 105.2 和 220 mg/L 降低到复合纳米吸附剂中的 0.5 和 16.4 mg/L。这些发现表明，新开发的复合纳米吸附剂可以吸附有机污染物，并靶向硫酸盐和硅酸盐阴离子，这使它们成为水和废水处理的合适候选物。
