| Phthalocyanine compound(Pc)is a synthetic organic compound with a macrocyclic conjugated structure.It is easy to synthesize a metal phthalocyanine coordination compound with a stable structure through complex reaction with many metal ions.Metal phthalocyanine has good photoelectric properties,electrical conductivity and electrocatalytic properties.First of all,in the research field of lithium ion anode materials,the theoretical specific capacity of traditional graphite anodes is limited,and the volume expansion and pulverization of the layered structure during the cycle will cause the attenuation of the battery capacity,which is not sufficient for the storage of large energy and high stability.Therefore,it is urgent to design a new type of lithium-ion battery anode material with high capacity,stable layered structure and superior cycle performance;secondly,in the research field of nonlinear optical limiting materials,phthalocyanine molecules have?electrons.The conjugated macrocyclic structure is very easy to agglomerate together,which greatly affects the photophysics and optical limiting performance.Therefore,based on the study of the mechanism of the phthalocyanine macrocyclic aggregation effect on its photophysical and optical limiting performance,it is possible to have The construction of an aggregation-free phthalocyanine molecular model with superior optical limiting performance provides a theoretical basis;third,in the research field of hydrogen production by electrocatalytic reduction,the traditionally used platinum-based precious metals are expensive,scarce and non-renewable,but low in price and performance The catalytic performance of stable phthalocyanine compounds is largely affected by the degree of aggregation and dispersion.Based on the above problems,this paper constructs a molecular model of a kind of sandwich layered phthalocyanine compound complexed with rare earth metals,and conducts the following three researches:(1)Construct a rare earth complex sandwich layered phthalocyanine compound(MPcs,M=La,Y,Yb,Sc)and use it as a new layered anode material for lithium-ion batteries.Explore the sandwich layer structure and its layer spacing for lithium-ion battery storage The influence law of energy performance.The results show that as the radius of rare earth metal ions decreases,the distance of the sandwich layered structure of rare earth phthalocyanine is gradually reduced(LaPc>YPc>YbPc>ScPc).At this time,the performance of the corresponding lithium ion battery is better..Among them,the ScPc phthalocyanine layered negative electrode with the smallest layer spacing can still maintain 534.98 m Ah/g after 500 cycles at a current density of 100 m A/g,showing the best cycle and rate performance.XPS mechanism research shows that the main reason for the higher specific capacity performance is that the rare earth phthalocyanine molecules formed by complexation have a stable layered structure and the molecular structure contains more activities such as C=C,N=O,and N=C.The structure realizes the reversible deintercalation reaction of lithium ions.(2)Construct a rare earth complex sandwich layered phthalocyanine compound(MPcs,M=La,Y,Yb,Sc),further study the influence of rare earth phthalocyanine with different central ions on optical limiting performance,and reveal the effect of aggregation on nonlinear optical effects Influence Mechanism.Hyperchem fitting results show that for the four phthalocyanine molecules LaPc,YPc,YbPc and ScPc,as the radius of rare earth ions decreases,the interlayer spacing between the phthalocyanine rings gradually decreases,and the degree of aggregation between the phthalocyanine rings Also increase.The results showed that the photophysical absorption coefficient and nonlinear absorption coefficient of different rare earth phthalocyanines also showed regular changes.At the same concentration,the nonlinear absorption coefficients(?)of the four rare earth phthalocyanines are LaPc(?=1.86×10-10 m/W),YPc(?=9.78×10-11 m/W),YbPc(?=9.63×10-11m/W),ScPc(?=7.43×10-11 m/W),indicating that as the radius of the rare earth metal changes from La,Y,Yb to Sc,the degree of aggregation between the phthalocyanine rings gradually increases,thus The reverse saturable absorption process is suppressed,resulting in a downward trend in the nonlinear optical absorption coefficient.The experimental results fully reveal the influence of the aggregation effect between the phthalocyanine rings on the photophysical and nonlinear optical properties,and provide a theoretical basis for the design of high-performance nonlinear optical materials.(3)Constructing rare earth complex sandwich layered phthalocyanine compounds(MPcs,M=La,Y,Yb,Sc),and compounding them with carbon materials to improve their dispersion,and further study the influence of different rare earth phthalocyanine electrocatalytic properties,aiming at phthalocyanines Cyanine compounds have the disadvantages of general conductivity and small active contact area.In this chapter,rare earth phthalocyanines with different central ions are compounded with carbon materials(graphene/carbon nanotubes)to form a material that has a rare earth metal-nitrogen-carbon structure.The central rare earth metal has a great influence on the electrocatalytic performance of the phthalocyanine composite.ScPc/Gr has the best electrocatalytic performance when the rare earth phthalocyanine is combined with graphene.The overpotential for hydrogen evolution of ScPc/Gr is 514 m V and the Tafel slope is 148 m V/dec.When the rare earth phthalocyanine is compounded with carbon nanotubes,LaPc/CNT has the best LSV performance,and the corresponding Tafel slope is also the smallest 176 m V/dec.This is mainly due to the different combination of rare earth phthalocyanine and carbon materials.When the rare earth phthalocyanine is combined with the layered graphene,it is more convenient for the phthalocyanine molecules to embed between the graphene layers or attach to the layered graphene when the rare earth phthalocyanine molecular structure is small.The graphene surface increases the active contact area.When the rare earth phthalocyanine is combined with the tubular carbon nanotubes,it is mainly attached to the surface or entangled by the carbon nanotubes.At this time,the rare earth phthalocyanine molecules are larger and easier to provide more More active sites,exert greater catalytic performance. |
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