Design,Synthesis And Photocatalytic Performance Of Metalloporphyrin MOFs-oxide

In recent years,as the total amount of energy available has gone from bad to worse,the development of new energy sources cannot be delayed.Photocatalyst technology shows great prospects in the field of cracking water to produce hydrogen.CuOand Cu₂O semiconductor materials have become one of the photocatalytic materials that have received wide attention due to their low cost,non-toxicity and chemical stability.However,the forbidden band width of CuOand Cu₂O is relatively wide,and electron-hole recombination is easy,which severely reduces the catalytic performance of their photocatalytic reaction,making it impossible to make full use of visible light.Therefore,this topic makes full use of the excellent light,thermal and chemical stability of the layered porphyrin MOFs as well as strong absorption in the visible light region.Based on 5,10,15,20-tetrakis（4-carboxyphenyl）porphyrin（HTCPP）,Zn TCPP-MOF,Co TCPP-MOF,Fe TCPP-MOF,Cu TCPP-MOF were prepared through metallization reaction.The CuOand Cu₂O were sensitized,and their structure and morphology were identified and analyzed by FT-IR,XRD,UV-Vis,fluorescence spectrum analysis and SEM.At the same time,the photocatalytic hydrogen production performance of different porphyrin MOFs of the central metal species,metal oxide species,and different metal oxide composite ratios were compared.The results showed that among the four metal porphyrin MOFs,the photocatalytic production of Co MOF.Using chemical reduction method,on the basis of Zn TCPP-MOFs,after inserting the column ligand（DS）into ZnMOFs,the disulfide bond of DS is broken by the strong reducibility of trimethylphosphine,The layered ZnMOFs were prepared.Determine its morphology and structure by XRD,FT-IR,SEM,TEM,XPS and other characterization methods.The results showed that the layered porphyrin MOFs with trimethylphosphine bond-breaking were successfully prepared and further sensitized to Cu O.Before Zn TCPP-MOFs sensitizes Cu O,the CuOis modified with isocyanate linker（L1）and alkyl isocyanate linking agent（L2）,and L1 and L2 are used as the bonding unit.Explore the effects of different experimental factors,including different p H conditions,and light source types on the rate of photocatalytic hydrogen production.The results show that the photocatalytic hydrogen production effect is the bestwhen the catalyst is the p H is 6.0,and the light source is xenon lamp.Based on the ZnMOFs-CuOof the above two systems,the effect of Pt as a metal promoter on the photocatalytic hydrogen production performance of the catalyst was explored.By light-depositing chloroplatinic acid on Ti O₂ and Cu O,and sensitizing them with ZnMOFs of the two systems respectively,the photocatalytic hydrogen production rate under the above optimal reaction conditions was investigated.The photocatalytic hydrogen production mechanism of Pt-modified layered metalloporphyrin MOFs sensitized CuOwas explored,and the key basic issues such as broadening the light response range and how to delay the electron pair-hole combination were analyzed to clarify the reasonable light catalytic mechanism.Through the above research,it is expected that water and methanol can quickly produce hydrogen under visible light at low cost and expand new ideas for the construction of visible light catalysts.