Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, China; Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing, 100084, China.
Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, China; Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing, 100084, China.
Chemosphere. 2021 Sep;278:130492. doi: 10.1016/j.chemosphere.2021.130492. Epub 2021 Apr 5.
In this study, a new adsorbent, polyvinyl alcohol (PVA) and graphene oxide (GO), was prepared, characterized and used for the removal of Sr from aqueous solution. In PVA/GO composite, the inter-lamellar spacing of adjacent GO layers was dramatically enlarged due to the intercalation of PVA molecules, such a unique architecture significantly mitigated the aggregation of GO layers, which facilitated the accessible exposure of active sites and the mass transfer of strontium ions (Sr), thus enhancing the adsorption capacity toward Sr. The adsorption of Sr by PVA/GO composite conformed to the pseudo second-order kinetic model (R = 0.9994), the Langmuir model (R = 0.9042), and the Freundlich model (R = 0.9598). The complexation interaction between Sr and oxygen atoms/π-electron domain of PVA/GO composite was primarily responsible for the adsorption mechanism, based on the characterization results of X-ray photoelectron spectroscopy (XPS), scanning electron microscope equipped with energy dispersion spectroscopy (SEM-EDS) and powder X-ray diffraction (PXRD).
在这项研究中，制备了一种新型吸附剂，即聚乙烯醇（PVA）和氧化石墨烯（GO），并对其进行了表征，用于从水溶液中去除 Sr。在 PVA/GO 复合材料中，由于 PVA 分子的插层作用，相邻 GO 层的层间距显著增大，这种独特的结构显著减轻了 GO 层的聚集，有利于活性位点的可及暴露和 Sr 离子的质量转移，从而提高了对 Sr 的吸附能力。PVA/GO 复合材料对 Sr 的吸附符合准二级动力学模型（R = 0.9994）、Langmuir 模型（R = 0.9042）和 Freundlich 模型（R = 0.9598）。基于 X 射线光电子能谱（XPS）、扫描电子显微镜配备能量色散光谱（SEM-EDS）和粉末 X 射线衍射（PXRD）的表征结果，Sr 与 PVA/GO 复合材料中氧原子/π 电子域之间的络合相互作用是吸附机制的主要原因。
