Construction And Properties Of Graphene-mediated Catalyst Systems For Photo-induced Hydrogen Production

Photo-induced hydrogen（H₂）production is regarded as a promising approach to direct conversion of solar energy into clean energy.The non-noble metal catalysts have been widely researched in the photo-induced H₂ production systems benefit from the inexpensive and the abundance.Simultaneously,the studies of the graphene and its derivatives in the photo-induced H₂ production systems are expected to be a hot topic in recent research.Around the topic,the following studies have been researched in this paper:1.A novel[FeFe]-hydrogenases model[Fe₂（μ-SC₃H₆S）（CO）₅][Fc（PPh₂）CHO]（1）,which contains a[3Fe2S]cluster,another novel[FeFe]-hydrogenases model5-{[Fe₂（μ-SC₃H₆S）（CO）₅]（PPh₂Fc）}-10,15,20-triphenylporphyrin（2）,which contains a photosensitizer group tetraphenylporphyrin and a photosensitizer TPP functionalized GO nanocomposite TPP-GO were designed and synthesized successfully.Then,we linked 1 and TPP-GO by covalent bond to prepare a novel nanocomposite TPP--GO-[3Fe2S]（3）,so as to fabricate a novel graphene-mediated[FeFe]-hydrogenases biomimetic photo-induced H₂ production system.The structure of the novel complex and the morphology of nanocomposite were characterized by elemental analysis,¹H NMR,¹³C NMR,³¹P NMR,Fourier transform infrared,X-ray crystallography,inductively coupled plasma atomic emission spectrometry and transmission electron microscopy,respectively.The electrochemical properties,the effect of electron transfer and the efficiency of photocatalytic H₂ production of different complexes and catalytic systems were compared and analyzed by cyclic voltammetry,ultraviolet-visible absorption,fluorescence emission,time-resolved fluorescence spectra and gas chromatography.2.Two[FeFe]-hydrogenases models[Fe₂（CO）₅（PPh₃）{μ-SC₆H₃（CH₃）S}]（B）and[Fe₂（CO）₅{Ph₂P（2-C₅H₄N）}{μ-SC₆H₃（CH₃）S}]（4）,which contain a[2Fe2S]cluster,were synthesized successfully.Then we combined the two models or mononuclear nickel complex（5）with TPP-GO by adsorbing to form biomimetic photo-induced H₂ production system.The structure of the new complex was characterized by ¹H NMR,¹³C NMR,³¹P NMR,Fourier transform infrared and X-ray crystallography.The electrochemical properties,the effect of electron transfer and the efficiency of photocatalytic H₂ production of different complexes and catalytic systems were compared and analyzed by cyclic voltammetry,ultraviolet-visible absorption,fluorescence emission,time-resolved fluorescence spectra and gas chromatography.