用于高效砷吸附的结构可控氧化铁功能化多孔碳材料的研究

Arsenic-containing water is very toxic and thus has a strong adverse effect on human health. To improve the quality of water, porous carbon based adsorbents have been extensively applied to remove arsenic from polluted water. However, these adsorbents show some disadvantages.: 1) The arsenic adsorption capacities are relatively low; 2) Arsenite cannot be removed efficiently; 3) The arsenic concentration after adsorption is higher than the standard suggested by World Health Organization. In addition, the arsenic adsorption mechanism in the porous structure has not been revealed, and the fundamental understanding on the structure-function relationship for nanoporous adsorbents used for arsenic removal has not been established, which hinders the development of new arsenic adsorbents with high performance. .To solve above issues, in this project, we will fabricate iron oxide functionalized porous carbon with controlled structures as the arsenic adsorbents. By controlling the loading process of iron oxide, even at a high loading amount of iron oxide, iron oxide can still homogeneously disperse in the pores of porous carbon rather than forming aggregates, which could generate more arsenic adsorption sites and thus improve the arsenic adsorption performance of porous carbon. Moreover, by controlling the mesostructure and structure parameters (such as pore size) of porous carbon materials, the arsenic adsorption mechanism in the porous carbon can be revealed, and the fundamental correlation between the porous structure and adsorption performance can be established. This project may provide guidelines for the design of arsenic adsorbents with high performance.

含砷饮用水有很强的毒性和致癌性，会危害人类的健康。如何有效除去饮用水中的砷使其达到饮用标准一直是国内外关注的一个研究课题。基于多孔碳材料的吸附剂被广泛用于除砷。现有吸附剂存在的问题包括砷吸附量低、吸附后不能满足饮用水标准、不能吸附亚砷酸盐等。此外，多孔碳材料中的砷吸附机理还不清楚，多孔碳材料的结构与砷吸附性能之间的关系还未被建立。本项目拟合成结构可控氧化铁功能化多孔碳材料作为高效砷吸附剂。通过控制负载氧化铁时的条件，使得在氧化铁含量很高的情况下，氧化铁在多孔碳材料的孔道内仍然是处于分散的状态，以此来增加活性砷吸附位点进而提高砷吸附性能。通过改变多孔碳材料的介观结构及孔径等结构参数，并对比材料的砷吸附性能，研究多孔碳材料中的砷吸附机理以及结构与砷吸附性能的关系。本研究有望为高效多孔砷吸附剂的设计与开发提供新的思路，并在含砷饮用水的处理方面得到重要应用。

含砷饮用水有很强的毒性和致癌性，长期饮用会对人体产生危害。为使水源符合饮用标准，基于多孔碳材料的吸附剂被广泛用于除去水中的砷。现有吸附剂存在砷吸附量低、吸附后不能满足饮用水标准、不能吸附亚砷酸盐等问题。此外，多孔碳材料的介观结构与砷吸附性能之间的关系也还未被建立。本项目针对这些关键问题，以介观结构及孔径不同的多孔碳材料作为基底材料来合成砷吸附剂，通过对比吸附剂的吸附性能，来建立多孔碳材料的介观结构以及孔径对吸附性能的影响。本项目主要在三个方面进行了探索：1、以不同的多孔碳材料作为基底材料，以硝酸铁作为铁源，通过湿法灌注的方法，制备得到γ-Fe2O3功能化的多孔碳材料。γ-Fe2O3在多孔碳的孔道内能够均匀分散，从而增加了活性砷吸附位点；2、通过对比不同介观结构的功能化多孔碳材料的砷吸附性能，发现孔道相对更为开放的二维六方结构的多孔碳材料的砷吸附性能更好；3、通过对比不同孔径的多孔碳材料的砷吸附性能，得到更大的孔径有利于砷吸附性能的进一步提高的结论。这些研究为高效的多孔砷吸附剂的设计与开发提供了一定的理论和实验依据，并且有望在含砷饮用水的处理方面得到应用。