Fabrication Of B/n Co-doped And N/P Co-doped Graphene Nanoplatelets And Their Catalytic Application In Organic Reaction

Graphene has an electronic structure that is different from other sp~2 carbons,and it has open edges,especially,when the size of graphene is reduced to nanoscale.The electronic properties at the edge are different from the bulk,which makes it possible to apply to catalysis.However,doped graphene has more applications in catalysis comparing with graphene.Because heteroatom doping can introduce bandgap and change its electronic structure,which further increase the catalytic activity.Therefore,the use of a simple and quick method for preparing doped graphene and applying in catalysis has a very high research value.In this paper,B/N co-doped graphene(BNG)and N/P co-doped graphene(NPG)were prepared for the catalytic reduction of nitrobenzenes and the oxidation of benzyl alcohols,respectively.In this paper,graphite was used as the raw material.Firstly,edge functionalized graphene nanoplatelets(EFGnPs)were prepared by ball milling.Then,BNG was synthesized by pyrolysis of a mixture of EFGnPs and boric acid.NPG was synthesized by pyrolysis of a mixture of EFGnPs and hexachlorocyclo-triphosphazene(HCCP).The morphology of the as-prepared material was examined by scanning electron microscopy(SEM),transmission electron microscopy(TEM)and atomic force microscopy(AFM).The defect degree and graphitization degree of the material were analyzed by Raman spectroscopy(Raman)and X-ray diffraction(XRD).X-ray photoelectron spectroscopy(XPS)has been utilized for analyzing the doping amount and bonding configuration of samples.The as-prepared BNG was used to catalyse the nitrobenzene reduction reaction.Our experiment used ethanol as solvent and a small amount of hydrazine hydrate as reductant.Adding 4 mg catalyst,99%yield was obtained after three hours of reaction.Combining the catalytic effect of BNG prepared at different calcination temperatures and the valence form of B in the catalyst,the main active component of catalyzing the reaction was analyzed.Furthermore,the paper has demonstrated that BNG has good applicability and recyclability through substrate development test and cycle test.In addition,the as-prepared NPG was used to catalyse the benzyl alcohol oxidation.Our experiment used water as the solvent and a new oxidation system,which t-butylhydroperoxide(TBHP)and oxygen are as the oxidant.Adding 7 mg of catalyst,the substrate can be oxidized to the corresponding acid with a 99%yield.NPG catalyzes the benzyl alcohol compounds with different functional groups to exhibit excellent catalytic performance with the high selectivity.Both of the above experiments have shown that BNG and NPG have a wide application space in the field of catalysis.The specific catalytic mechanism needs further research by researchers.