Preparation,Characterization And Properties Of Cationic Phthalocyanine/Graphene Composites

Graphene is an outstanding material,consisting of a two dimensional(2D)single layer of sp2-hybridized carbon atoms and possesses excellent electronic and optical properties.Its thin plane geometry,unusual band structure and high carrier mobility make it an ideal material for applications in future optoelectronic devices.It is easy to be modified through introducing different kinds of functional molecules onto its surface by covalent or non-covalent method.Functionalized GO can be applied in many fields.In this work,four novel cationic metallophthalocyanines modified GO nanocomposites through non-covalent method were synthesized and characterized.The optoelectronic transformation properties and photocatalytic properties of these nanocomposites were investigated respectively.Four cationic phthalocyanine ZnPc,CuPc,CoPc and NiPc were synthesized through introducing four imidazole cationic substituents to the phthalocyanine ring firstly.The structure of these complexes were characterized by 1H-NMR,MS,UV-vis spectrum,IR spectrum and element analysis.Their electrochemical properties were studied by cyclic voltammetry method.In addition,these complexes all showed excellent solubilities in water and methanol.Four new composites ZnPc-GO,CuPc-GO,NiPc-GO and CoPc-GO were synthesized through utilizing the ?-? interaction between the Pc molecules and the graphene oxide sheet.The structure of the Pc-GO hybrids were characterized by IR spectrum,UV-Vis spectrum,XRD,TEM and XPS methods.A red-shifted and broadened Q-band of these phthalocyanines were found after being adsorbed on the surface of graphene oxide in the UV-Vis absorption spectra of these composites.Therefore,we can speculate there are ?-? interaction between the Pc molecule and GO.These Pc-GO hybrids showed good dispersion in water.All these hybrids have not been reported.The photoelectric conversion properties of the composites ZnPc-GO,CuPc-GO,NiPc-GO and pure GO as electrode materials were investigated respectively in a solar cell.The Pc-GO film on FTO substrate gave a obviously reversible rise/decay of the photocurrent in response to the on/off illumination step and the photocurrent intensity are 6?40 times higher than the pure GO film.Therefore,the hybrids ZnPc-GO and CuPc-GO and NiPc-GO have potential applications as a photoelectric conversion material in dye sensitized solar cell.At last,the photocatalytic activities of composites CoPc-GO and NiPc-GO for degradation of RhB under visible light irradiation were studied.Under the optimized experimental conditions with the catalyst concentration=0.6 g/L and pH=6.9,the degradation of RhB rate were 92%and 91%when using CoPc-GO and NiPc-GO hybrids as catalyst respectively after 3h irradiation.In addition,the catalyst can be recycled for 3 times with a little decrease in activity.