Fabricating a graphene oxide—bayberry tannin sponge for effective radionuclide removal
Fabricating a graphene oxide—bayberry tannin sponge for effective radionuclide removal
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DOI：
10.1088/2053-1591/3/5/055002
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发表时间：
2016-04
影响因子：
2.3
通讯作者：
Xiao Deng;Xiaonan Liu;Tao Duan;Wenkun Zhu;Zao Yi;Weitang Yao
中科院分区：
文献类型：
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作者：
Xiao Deng;Xiaonan Liu;Tao Duan;Wenkun Zhu;Zao Yi;Weitang Yao
以杨梅单宁为还原剂和表面功能化剂，采用自组装法制备了杨梅单宁（BT）还原氧化石墨烯（rGO）海绵。该合成方法是基于氧化石墨烯（GO）片自组装成多孔水凝胶结构。通过改变GO与BT的重量比，获得了一系列具有不同有机分子密度的吸附剂，并将其应用于从水溶液中去除Sr 2+。吸附等温线（Langmuir和Freundlich）和动力学（伪一级和伪二级）进行了研究，以讨论吸附性能的rGO/BT海绵。rGO/BT（w/w 1：1）海绵对Sr 2+表现出优异的吸附性能，最大容量为67.98 mg g−1。吸附容量远高于经典的Sr 2+吸附剂，如水合二氧化锰，埃及土壤，羟基磷灰石纳米颗粒，六钛酸钠纳米纤维，氧化石墨烯，人工改变金云母（Ca-Phl），PB/Fe 3 O 4/GO。利用X射线光电子能谱（XPS）研究了吸附剂吸附Sr ~（2+）前后的吸附机理，结果表明，Sr ~（2+）在GO和GO/BT 1.0上的吸附主要取决于含氧官能团。结果表明，GO/BT海绵是一种很有前途的Sr 2+吸附材料。
Bayberry tannin (BT)–reduced graphene oxide (rGO) sponges have been prepared by self–assembly, with bayberry tannin serving as both reductant and surface functionalization agent. The synthetic method is based on the self-assembly of graphene oxide (GO) sheets into porous hydrogel structures. By varying the weight ratio of GO to BT, a series of sorbents with different densities of organic molecules have been obtained and applied to remove Sr2+ from aqueous solutions. Adsorption isotherms (Langmuir and Freundlich) and kinetics (pseudo-first order and pseudo-second order) have been investigated to discuss the sorption performance of rGO/BT sponges. The rGO/BT (w/w 1:1) sponge shows excellent adsorption properties for Sr2+, with maximum capacities of 67.98 mg g−1. The adsorption capacity is much higher than those in classic Sr2+ adsorbents, such as hydrous manganese dioxide, Egyptian soils, Hydroxyapatite nanoparticles, sodium hexa-titanate nanofibers, Graphene oxide, artificially altered phlogopite(Ca–Phl), and PB/Fe3O4/GO. Adsorption mechanisms have been examined using the x-ray photoelectron spectra of sorbents before and after Sr2+ adsorption, and the results indicate that the sorption of Sr2+ on GO and GO/BT 1.0 is largely depended on oxygen functional groups. The results show that the GO/BT sponge is a promising candidate for adsorbing Sr2+ ion.