Fabrication And Application Of Hierarchical Layer By Layer Assembled Diamond Based Core-shell Nanocomposites

Nowadays with the rapid development of industry,much attention has been paid for the issue of water pollution.The comprehensive treatment of industrial wastewater has become a huge challenge that the world environmental organization needs to solve urgently.How to prepare adsorbents and catalysts with large specific surface area,suitable pore size structure,and easy separation from solution has become a difficult problem.In this paper,a variety of diamond nanomaterials were designed and synthesized as adsorbents and catalysts for wastewater treatment,and their adsorption and catalytic effects were also discussed.Firstly,the diamond@graphite was obtained by the technique of Spark Plasma Sintering using diamond.Then we used the modified Hummers method to prepare the diamond@graphene oxide by diamond@graphite.The core-shell carboxyl-functionalized diamond@graphene oxide was synthesized by the chemical modification of chloroacetic acid on the surface of diamond@graphene oxide.The adsorbents core-shell diamond-based nanomaterials which have the advantages of large specific surface area,mesoporous structures and easy separation from solution was obtained by the reaction of carboxyl-functionalized diamond@graphene oxide,polyethylenimine and polyacrylic acid using the layer-by-layer assembled strategy.Then adsorption experiments were carried out for the adsorbent with the dyes of MB and RhB solution.And the results showed that this adsorbent presented good performance and high recyclability.Specifically,the equilibrated adsorption capacity for MB solution was about41.3414 mg/g.Similarly,the core-shell diamond-based nanomaterials used as catalytic carrier were successfully synthesized with the reaction of carboxyl-functionalized diamond@graphene oxide,polyallylamine hydrochloride and polyacrylic acid using the layer-by-layer assembled method.Then the gold nanoparticles which were prepared by the reaction of HAuCl₄ and NaBH₄ were modified on the catalytic carrier to get the catalyst,and discussed the catalytic efficiency for the 4-nitrophenol solution.The prepared nanocomposites exhibited high activity and recyclability.The prepared catalyst carrier increased the loading of gold particles and also easily separated from the solution,becoming an environment-friendly new nanomaterial.The catalyst diamond@graphene oxide@gold nanoparticles were carried out by the modification of gold nanoparticles on the surface of diamond@graphene oxide,and investigated the catalytic activity for the solution of 4-nitrophenol and 2-nitroaniline.The obtained nanocomposites demonstrated excellent catalytic activity and high recyclability.Graphene oxide with porous structure and high specific surface area increased the loading of gold particles.At the same time,the core of diamond solved the separation of the catalyst from solution.The nanocomposites opened up a new field for the preparation of catalysts.