The new adsorption rate of domestically produced graphene film is high
Antibiotics are one of the most widely used types of drugs. A few days ago, according to the "Science Bulletin" report, China's surface water contains 68 kinds of antibiotics, and the concentration is high. In addition, 90 non-antibiotic pharmaceutical ingredients were detected. However, the current water treatment technology is still difficult to completely remove trace antibiotics in water, and the development of efficient decontamination devices is particularly urgent.
Recently, Professor Li Haitao of Jiangsu Normal University has successfully developed a graphene multifunctional composite membrane. According to research published in the journal Nature Reports, the ultra-light and ultra-thin graphene-activated carbon film adsorption efficiency can reach 99.99% for granular objects including antibiotics.
“Many studies are based on various types of nanomaterials and have constructed a series of novel ultra-thin and high-permeability functional separation membranes. Among these nanomaterials, graphene oxide nanofilms as a typical monoatomic The nano-materials have a very high separation efficiency and become a brand new thin layer separation membrane," Li Haitao said. However, the filter membrane prepared by pure graphene oxide has a small interlayer spacing, resulting in insufficient water permeation flux, long time consumption, high pressure resistance and brittleness.
In order to solve this problem, Li Haitao's research group inserted activated carbon (AC) into a thin film of graphene oxide (GO) to prepare a composite porous carbon film micro-nano material.
The activated carbon (AC) nanoparticle structure itself has unique functional groups such as carboxyl group, carbonyl group, phenol, lactone, hydrazine, etc., which can effectively increase the adsorption capacity of the composite membrane itself.
"We have used a synergistic effect between activated carbon materials to prepare a composite film material based on graphene oxide, which has achieved complete removal of antibiotic substances in the reference water." Li Haitao said.
The surface of graphene oxide is rich in oxygen-containing functional groups. By means of "π-π" action and van der Waals force, graphene oxide has good adsorption effect on various organic substances.
"The addition of nano-activated carbon not only plays a good role in supporting the framework of graphene oxide sheets, but also greatly improves the adsorption capacity of graphene film materials." Li Haitao said that at the same time, activated carbon materials effectively increase graphite oxide. The interlayer distance of the olefin can effectively improve the specific surface area of the film material.
Experiments show that compared with other materials, the composite has good tolerance to strong acid and alkali, and has a wide application range.
"In this study, we explored in depth the mechanism of removal of residual tetracycline hydrochloride (TCH) from water by a composite membrane material consisting of two-dimensional graphene oxide/one-dimensional activated carbon material," Li Haitao said.
It has been found that the flexible graphene oxide/activated carbon composite membrane exhibits a very strong adsorption capacity for tetracycline hydrochloride (TCH) molecules. Li Haitao explained that this good adsorption performance mainly comes from the good interaction between graphene oxide and activated carbon and antibiotic molecules. However, the simple graphene oxide film will be seriously stacked, and the activated carbon material is prone to agglomeration effects.