Here, a novel adsorbent for selective separation and recovery of In(III) ions from the real wastewater was fabricated using ion imprinting technique with graphene oxide composite as the host materials. Several techniques, including Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetry (TGA) and Brunauer–Emmett–Teller (BET)were used to characterize the silica gel/graphene oxide based ion-imprinted composites (SG/GOIIC) and the obtained experimental results were combined with the Density Functional Theory (DFT) theoretical calculations to reveal the adsorption mechanism. The adsorption behaviors of SG/GOIIC towards In(III) ions was evaluated using both batch and fixed-bed experiments. The results shown that the adsorption ability of In(III) ions onto SG/GOIIC increased with the increase of pH range from 1.5 to 3.0, and that the adsorption equilibrium was reached within 50 min. The maximum uptake of SG/GOIIC calculated using Langmuir isotherm was estimated to 147.1 mg/g. Kinetics studies revealed that the pseudo-second-order was a better choice to describe the whole absorption process, while the isotherms of In(III) ions adsorption followed the Langmuir model. In addition, SG/GOIIC exhibited excellent affinity towards In(III) ions in water even in the presence of Sn(II), Cu(II), Zn(II), Al(III) and Fe(III) ions and the corresponding selectivity coefficients of SG/GOIIC for In/Sn, In/Cu, In/Zn, In/Al and In/Fe were 18.47, 22.99, 35.31, 16.67 and 8.52, respectively. The SG/GOIIC possessed good stability with adsorption rate maintained at 94.36% even after five cycles. More importantly, the SG/GOIIC composite was able to separate and to recover indium from real wastewater through fix-bed adsorption. This study proposed a new method to prepare adsorbent with excellent selectivity towards targeted ions and to figure out the difficulty of graphene oxide in separation from water.

在这里，使用离子印迹技术，以氧化石墨烯复合材料为主体，制备了一种用于从实际废水中选择性分离和回收In（III）离子的新型吸附剂。几种技术用于表征硅胶，包括傅立叶变换红外光谱（FT-IR），扫描电子显微镜（SEM），X射线光电子能谱（XPS），热重分析（TGA）和Brunauer–Emmett–Teller（BET）。 /氧化石墨烯基离子印迹复合材料（SG / GOIIC）以及获得的实验结果与密度泛函理论（DFT）理论计算相结合，揭示了吸附机理。使用分批和固定床实验评估了SG / GOIIC对In（III）离子的吸附行为。结果表明，随着pH值从1.5增加到3.0，In（III）离子对SG / GOIIC的吸附能力增强，并且在50min内达到吸附平衡。使用Langmuir等温线计算得出的SG / GOIIC的最大吸收量估计为147.1 mg / g。动力学研究表明，拟二阶是描述整个吸收过程的较好选择，而In（III）离子的吸附等温线遵循Langmuir模型。此外，即使存在Sn（II），Cu（II），Zn（II），Al（III）和Fe（III）离子及其相应的离子，SG / GOIIC对水中的In（III）离子也显示出优异的亲和力SG / GOIIC对In / Sn，In / Cu，In / Zn，In / Al和In / Fe的选择性系数分别为18.47、22.99、35.31、16.67和8.52。SG / GOIIC具有良好的稳定性，即使经过5个循环，吸附率仍保持在94.36％。更重要的是，SG / GOIIC复合材料能够通过固定床吸附分离并从实际废水中回收铟。这项研究提出了一种新的方法来制备对目标离子具有优异选择性的吸附剂，并解决了氧化石墨烯与水分离的难题。