Department of Applied Chemistry, University of Johannesburg, Doornfontein Johannesburg 2028, South Africa.
Department of Applied Chemistry, University of Johannesburg, Doornfontein Johannesburg 2028, South Africa.
J Colloid Interface Sci. 2018 Dec 15;532:500-516. doi: 10.1016/j.jcis.2018.07.134. Epub 2018 Jul 31.
Hydrous CeO-FeO (HCeFe) decorated polyaniline nanofibers (HCeFe NFs) were obtained through a simple co-precipitation deposition approach on pre-synthesized polyaniline nano-fibers (PANI NFs), and evaluated as adsorbents for fluoride removal from synthetic and real water samples. Field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FE-SEM/EDS), high resolution-transmission electron microscopy (HR-TEM), Braunauer-Emmett-Teller (BET), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric-differential thermal analysis (TGA-DTA), X-ray photoelectron spectroscopy (XPS) and dynamic mechanical analysis (DMA) techniques were used to characterize the hybrid nanomaterials. The optimised HCeFe NFs adsorbent with specific surface area 66 m/g, exhibited excellent adsorption efficiency towards fluoride ions (F) via both electrostatic interactions and ion exchange mechanisms. F adsorption followed the pseudo-second-order rate model and best fitted the Langmuir isotherm, with the maximum capacities within 93.46-117.64 mg/g over a broad pH range 3-10, respectively. The determined thermodynamic parameters, including enthalpy (ΔH° - 15.1 kJ/mol) and Gibbs free energies change (ΔG° < 0) indicated to the exothermic and a spontaneous nature of the sorption process. The regeneration of HCeFe NFs showed a considerable adsorption-desorption efficiency over three consecutive cycles. Ultimately, the adsorbent was tested on spiked F containing groundwater and the obtained results demonstrated its potential utility for defluoridation of natural water.
水合氧化铈-氧化亚铁（HCeFe）修饰的聚苯胺纳米纤维（HCeFe NF）是通过在预先合成的聚苯胺纳米纤维（PANI NF）上采用简单的共沉淀沉积方法获得的，并作为吸附剂用于从合成和实际水样中去除氟化物。场发射扫描电子显微镜/能谱（FE-SEM/EDS）、高分辨率透射电子显微镜（HR-TEM）、BET、X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、热重-差示热分析（TGA-DTA）、X 射线光电子能谱（XPS）和动态力学分析（DMA）技术用于对杂化纳米材料进行表征。优化的 HCeFe NF 吸附剂比表面积为 66m/g，通过静电相互作用和离子交换机制对氟离子（F）表现出优异的吸附效率。F 吸附遵循伪二级速率模型，最佳拟合 Langmuir 等温线，在 3-10 的宽 pH 范围内，最大容量分别为 93.46-117.64mg/g。确定的热力学参数，包括焓（ΔH°-15.1kJ/mol）和吉布斯自由能变化（ΔG°<0）表明吸附过程是放热和自发的。HCeFe NF 的再生在三个连续循环中表现出相当高的吸附-解吸效率。最终，该吸附剂在含 F 的地下水的加标水样中进行了测试，结果表明其在天然水除氟方面具有潜在的应用价值。
