School of Chemistry and Chemical Engineering, Qinghai Normal University, Xining, 810008, Qinghai, China.
Environ Sci Pollut Res Int. 2020 Aug;27(22):28396-28407. doi: 10.1007/s11356-020-08018-6. Epub 2020 May 16.
With the development of the boron industry, boron pollution is getting more and more serious, and excessive boron will harm human health. In this paper, graphene oxide was used as a template to prepare ZIF-67, and GO/ZIF-67 was successfully prepared. GO/ZIF-67 was used for the first time to remove boron from water. SEM, XRD, and other characterization methods were used to confirm the structure. The adsorption kinetics, adsorption isotherm, adsorption thermodynamics, and adsorption mechanism of boron by GO/ZIF-67 were studied in this paper. The adsorption capacity of GO/ZIF-67 for boron is up to 66.65 mg·g at 25 °C, and adsorption process reaches equilibrium in 400 min. Adsorption kinetics indicates that the adsorption process conforms to the pseudo-first-order kinetic model, and adsorption thermodynamics indicates that the adsorption process is a spontaneous endothermic process controlled by entropy change. The adsorption capacity of boron by GO/ZIF-67 does not decrease significantly after four cycles. The adsorption of boron by GO/ZIF-67 has both chemical and physical adsorption. From Zeta potential and adsorption kinetics, it can be seen that there is physical adsorption during the adsorption process and boron mainly has positive charge on the surface of GO/ZIF-67 and graphene oxide hydroxyl bonding. Based on the adsorption thermodynamics and XPS, it is known that there is chemisorption during the adsorption process, and mainly the combination of boron and cobalt sites.
随着硼工业的发展，硼污染越来越严重，过量的硼会危害人体健康。本文以氧化石墨烯为模板制备了 ZIF-67，并成功制备了 GO/ZIF-67。GO/ZIF-67 首次被用于从水中去除硼。通过 SEM、XRD 等表征方法确认了结构。本文研究了 GO/ZIF-67 对硼的吸附动力学、吸附等温线、吸附热力学和吸附机制。GO/ZIF-67 对硼的吸附容量在 25°C 时高达 66.65mg·g，吸附过程在 400min 内达到平衡。吸附动力学表明吸附过程符合拟一级动力学模型，吸附热力学表明吸附过程是一个自发的吸热过程，由熵变控制。GO/ZIF-67 对硼的吸附在经过四个循环后没有明显下降。GO/ZIF-67 对硼的吸附既有化学吸附又有物理吸附。从 Zeta 电位和吸附动力学可以看出，吸附过程中有物理吸附，硼主要在 GO/ZIF-67 和氧化石墨烯羟基键合表面带正电荷。根据吸附热力学和 XPS，可知在吸附过程中存在化学吸附，主要是硼与钴位的结合。
