Preparation Of Boron And Nitrogen Co-Doped Mesoporous Carbon Nanosheets And Removal Performance Of Tapical Organic Pollutants

With the development of society and industrialization,the problem of water pollution has become an environmental problem that needs to be solved urgently.The direct discharge of a large amount of waste dyes and antibiotics in the water seriously pollutes the water environment and poses a great harm to the ecological environment and human health.Common methods for removing organic pollutants are adsorption and Fenton oxidation.The adsorption technology is easy to operate,economical,effective,and reusable.It is considered to be the most commonly used method to remove water pollutants.Carbon materials are currently the most common adsorbent due to their cheap,easy availability and better adsorption capacity.The Fenton method uses Fenton reagent to activate H₂O₂ to produce intermediates with strong oxidizing properties to oxidize and degrade organic molecules.It is a simple and efficient treatment method.Moreover,H₂O₂is a green oxidant,which generates water after decomposition,which will not cause secondary pollution.However,common metal-containing Fenton agents may cause metal leaching and loss of active sites.It also reduces the catalytic performance while causing secondary pollution.The mesoporous carbon nanosheets co-doped with boron and nitrogen prepared in this paper are economical,efficient,and environmentally friendly non-metallic carbon materials.Combining the strong adsorption effect of mesoporous carbon on pollutant molecules with the Fenton-like reaction,it can effectively remove organic pollutants in water in a short time and can be applied to sewage treatment.Using melamine,diboron trioxide and macro-porous resin AB-8 as raw materials,boron and nitrogen co-doped mesoporous carbon nanosheet(AB-BCN-900)was prepared by chemical vapor deposition.The sample analysis and characterization results show that the material has a two-dimensional lamellar structure with a high specific surface area(2317.9 m²·g^-1),a large number of mesoporous structures and a pore volume of 14.10 cm³·g^-1.The doping of heteroatoms has an important effect on the structure of the material.Compared with AB-CN-900 without boron atoms,the specific surface area and pore volume of the material are increased by 2.36 times and2.66 times.The high specific surface area and mesoporous structure of mesoporous carbon nanosheets are beneficial to the removal of pollutant molecules in water.The prepared mesoporous carbon nanosheets are applied to the study of the adsorption performance of organic pollutants rhodamine B,methyl orange and tetracycline in wastewater.Compared with activated carbon,the AB-BCN-900material has higher adsorption capacity.The mesoporous structure of AB-BCN-900solves the problem of poor mass transfer performance of large-size molecules in the micropores of activated carbon.Its high specific surface area can expose more adsorption sites.Their combined effect makes AB-BCN-900 material has strong adsorption capacity for all three organic pollutants,and can adsorb a large amount of organic pollutants in a short time.In the Fenton oxidative degradation reaction,AB-CN-900 without boron atoms can not activate H₂O₂ to degrade organic pollutants.In materials doped with boron atoms,the doping of B atoms promotes H₂O₂ to generate strong oxidizing free radicals to act on organic pollutant molecules,effectively removing organic pollutants rhodamine B,methyl orange and tetracycline.