Method for preparing nanometer zero-valent iron with modified graphene oxide as carrier

Abstract

The invention discloses a method for preparing wrapped nanometer zero-valent iron with modified graphene oxide as a carrier. The method comprises the following steps that firstly, wrapped nanometer zero-valent iron is prepared; secondly, graphene oxide is modified; thirdly, the obtained modified graphene oxide is added to water, graphene oxide suspension liquid is obtained after ultrasonic dispersion is conducted for one to three hours, then the obtained wrapped nanometer zero-valent iron is added to the graphene oxide suspension liquid, filtering, washing and drying are conducted after stirring is conducted sufficiently, and then the wrapped nanometer zero-valent iron adsorbent with the modified graphene oxide as the carrier is obtained. According to the method, cheap and harmless tea polyphenol, agar and water soluble starch are taken as the surface modifier to prepare the wrapped nanometer zero-valent iron, and the target pollutant removal rate is increased; the surface of the graphene oxide is modified by means of covalent bonds, the maximum Cr6+ absorption capacity of the modified graphene oxide is 390 mg / g, and the absorption capacity is greatly improved by one to two times.

Description

technical field [0001] The invention relates to the field of nanometer materials, in particular to a method for preparing encapsulated nanometer zero-valent iron with modified graphene oxide as a carrier. Background technique [0002] Due to its strong reducing ability and cheap and easy-to-obtain raw materials, nano-zero-valent iron is not easy to cause secondary pollution during use, and it can efficiently remove pollutants in sediment or water, such as halogenated organic compounds, nitroaromatic compounds, and heavy metal ions. It has great application prospects in the field of wastewater treatment. [0003] In the Chinese Invention Patent Application Publication No. 201110211774.5, a method for preparing nano-zero-valent iron based on the liquid-phase complexation reduction method is disclosed. The soluble ferrous salt and the complexing agent sulfosalicylic acid are dissolved in water to adjust the pH value of the solution. 5 to 7 to form a complexed ferrous solution;...

AI Technical Summary

Problems solved by technology

[0004] The existing nano-zero-valent iron still has many limitations in practical applications, mainly reflected in: the high activity of nano-zero-valent iron, which will react with oxygen and water in water, thereby reducing the removal rate of target pollutants; The activity of zero-valent iron increases under acidic conditions, but acidic conditions will corrode equipment in practical applications; nano-zero-valent iron is difficult to recover in aqueous solution, and nano-zero-valent iron particles are prone to agglomeration in solution, which greatly reduces its reactivity and utilization efficiency

In addition, although the surface of graphene oxide materials has active groups such as hydroxyl, carbonyl and carboxyl groups, which can interact with metal ions, its selectivity is not satisfactory.