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The adsorption rate of domestic new graphene film reaches a new high.

Release time:

2017-04-14

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Antibiotic drugs are one of the most widely used types of drugs. A few days ago, according to the "Science Bulletin" report, my country's surface water contains 68 kinds of antibiotics with high concentrations. 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, the research group of Professor Li Haitao of Jiangsu Normal University took the lead in successfully developing a graphene multifunctional composite film. According to research results published in the "Nature" sub-journal "Scientific Reports", this ultra-light and ultra-thin graphene-activated carbon film has an adsorption efficiency of up to 99.99 percent for granular objects including antibiotics.

"Many studies have built a series of novel ultra-thin and high-flux functional separation membranes based on various types of nanomaterials. Among these nanomaterials, graphene oxide nanofilms, as a typical single-atom two-dimensional nanomaterial, have extremely high separation efficiency and become a new kind of thin-layer separation membrane." Li Haitao said. However, the filter membrane prepared by pure graphene oxide has a very small layer spacing, resulting in insufficient water permeation flux, long time consumption, intolerance to high pressure and fragility.

In order to solve this problem, Li Haitao's research group inserted activated carbon (AC) into graphene oxide (GO) thin layer membrane to prepare a composite porous carbon membrane micro-nano material.

The activated carbon (AC) nanoparticle structure itself has unique functional groups, such as carboxyl, carbonyl, phenol, lactone, quinone, etc., which can effectively increase the adsorption capacity of the composite membrane itself.

"We used the synergy between activated carbon materials to prepare a composite film material based on graphene oxide, which achieved complete removal of antibiotics in the cited water." Li Haitao said.

The surface of graphene oxide is rich in oxygen-containing functional groups. With the help of "π-π" effect and van der Waals force, graphene oxide has a good adsorption effect on a variety of organic compounds.

"The addition of nano-activated carbon not only plays a good skeleton support role between graphene oxide sheets, but also greatly improves the adsorption capacity of graphene film materials." Li Haitao said that at the same time, the activated carbon material effectively increases the interlayer distance of graphene oxide and realizes the effective increase of the specific surface area of the film material.

Experiments show that, compared with other materials, the composite material has a good resistance to strong acid and alkali, and has a wide range of applications.

"In this study, we deeply explored the removal mechanism of residual tetracycline hydrochloride (TCH) in water by the composite membrane material composed of two-dimensional graphene oxide/one-dimensional activated carbon material." Li Haitao said.

The study found that the flexible graphene oxide/activated carbon composite film showed 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 severely stacked, and the activated carbon material is prone to agglomeration effect.