The Synthesis Of Organic Dye-sensitized Graphene And Semiconductor And Their Photoelectron Transfer,Photocatalytic Hydrogen Evolution Properties

Nowadays,hydrogen as an environmentally friendly energy carrier with high capacity has attracted great attention owing to the increasing environmental concerns and energy demands.Photocatalytic water splitting to produce hydrogen has been regarded as one of the most promising strategies to convert solar energy into fuels.In this paper,we report synthesis of manganese porphyrin?MnTPP?functionalized graphene,manganese porphyrin sensitized copper ferrite semiconductor and Eosin Y sensitized copper ferrite semiconductor.The photoelectrochemical properties of the prepared photocatalysts and their catalytic efficiency were systematically studied.The main contents are summarized as follows:?1?Graphene oxide?GO?sheets covalently functionalized with?5,10,15,20-tetraphenyl?porphinato manganese?III??Mn TPP?has been successfully synthesized and tested as a photocatalyst for hydrogen evolution from water under UV-vis light irradiation.The obtained sample was systematically characterized by scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,UV-vis,Fourier transform infrared?FTIR?,and Raman spectroscopy.The results show that the MnTPP moiety has been successfully grafted on the graphene oxide surface to form MnTPP modified GO?GO-MnTPP?.The fluorescence quenching and photocurrent enhancement of GO-MnTPP confirm that the rapid electrons transfer from photoexcited the MnTPP moiety to the GO sheets.The platinized GO-MnTPP exhibits enhanced photocatalytic activity for water reduction to produce hydrogen.Moreover,with the assistance of polyvinyl pyrrolidone?PVP?,the photocatalytic activity is further improved because of aggregation prevention of the GO-MnTPP nanocomposite.This study provides a facile method to build porphyrin-graphene-based photocatalysts for solar energy conversion.?2?Light driven water splitting can be achieved through a tandem dye-sensitized photoelectrochemical cell.The photocathode is constructed by the Pt photodeposition on the surface of the p-type CuFe₂O₄-based photocathode sensitized with the?5,10,15,20-tetraphenyl?porphinato manganese?III?chloride?MnTPP?.Photoelectrochemical?PEC?water splitting performance was examined in detail.The results show that hydrogen was produced on the PEC device with the platinized MnTPP/CuFe₂O₄ and under the same conditons,no H₂ was produced with CuFe₂O₄ electrode.This work demonstrates a facile method to develop efficient photocathode materials for solar water splitting.?3?The copper ferrite semiconductor was prepared by hydrothermal method,and the EY was loaded onto Cu Fe₂O₄ semiconductor through ultrasonic-assisted method.The samples were characterized by transmission electron microscopy and photocurrent measurement.The results show that when the mass fraction of EY was 60%,the catalytic activity of CuFe₂O₄-EY reached the highest under visible light irradiation.This work provides a new idea for future dye-sensitized semiconductor.