| The nitrogen-doped mesoporous carbon nanospheres(N-MCNs)with high specific area,large pore size,excellent thermal stability,tunable particle size and pore structure have been widely used in drug deliver,adsorption,catalytic separation,electrochemical electrode materials and so on.To date,various synthetic strategies,such as hydrothermal process,hard-template assisted procedure,extended st?ber method and one-step aqueous route have been developed to fabricate N-MCNs.However,hydrothermal process often obtained the aggregation morphologies with only microporous structures,the hard-template assisted procedure always needed multi-steps with high cost and the extended st?ber method was strict to the carbon precursors.Recently,aqueous strategy was considered to be the most contentious and low-cost method,which gained more and more attentions.In this study,the fabrication of N-MCNs via the aqueous self-assembly strategy under high acid conditions was demonstrated and a possible mechanism was proposed to explain the co-assembly of carbon precursor and templates through the colloidal silica driving method.The ferric nitrate was chosen as magnetic resource to synthesize the functional mesoporous materials.Moreover,the morphology and mesoporous structure of the carbon nanospheres were facilely tuned by varying the ratio of alcohol/water,the concentration of HCl as well as the amount of F127.Besides,indomethacin,carbamazepine,acid red and basic fuchsin were chosen as drugs or dye models to investigate the drug release and dye adsorption properties of the carbon materials.More importantly,the present work affords a paradigm for the preparation of spherical mesoporous carbon nanoparticles through aqueous driving-induced assembly.The main contents of this paper are summarized as follow:(1)The nitrogen-doped microporous carbon nanospheres(N-CNs)were fabricated with 3-aminephenol as carbon and nitrogen precursor,F127 as soft-template and HCl as catalyst.In this process,the polymerization rate of carbon precursor was so fast that F127 was hardly combined into the self-assembly process.As a result,the F127 acted as an interface stabilizing agent rather than a template,and the material with microporous structures was obtained.Moreover,indomethacin with poor water-solubility was chosen as drug model and loaded into the obtained N-CNs.The release testing was carried out to investigate the release behavior of drug-loaded materials.(2)A colloidal silica nanoparticles driving co-assembly strategy was demonstrated for the first time to fabricate the nitrogen-doped dual-mesoporous carbon nanospheres(N-DMCNs).Colloidal silica not only acted as a pore-forming agent but also as a driving agent to induce the co-assembly of carbon precursors and templates,and a possible mechanism involved in a combined mechanism of both reversible reaction and nuclei growth was proposed.Interestingly,the mesoporous structure and particle sizes could be facilely tuned by varying the HCl concentrations,and the monodispersed nanospheres material with duel-mesoporous structure were finally obtained.Furthermore,carbamazepine,which was selected as the model drug,was loaded into the N-DMCNs,and a comparative study of the release of drug-loaded N-DMCNs and N-CNs were conducted to investigate their release behaviors.(3)The nitrogen-doped magnetic mesoporous carbon nanospheres(N-MMCNs)was synthesized with methenamine as the control-release agent of formaldehyde.The polymerization rate of carbon precursors was reduced by the control release of formaldehyde,which was benefit for the self-assembly of the carbon resource and template,and eventually obtained the well designed meseporous strctures.Besides,ferric nitrate not only acted as the magnetic resource but also the curing agent to solidify the morphology of obtained materials.As a result,the obtained material exhibited excellent thermal stability and recyclability.Moreover,acid red and basic fuchsin were chosen as the model pollutants to investigate the dye adsorption property of the N-MMCNs. |
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