Performances Of 1,10-Phenanthroline-phosphine Ligand Based Complexes Toward Photoenhanced Electrocatalytic Hydrogen Evolution Reaction

Decarbonization of the world economy is requiring hydrogen as an attractive energy source,while the design and preparation of high-active catalysts has become one major topic among the water splitting hydrogen evolution reactions(HER).In this thesis,we designed a new hybrid ligand N-((diphenylphosphanyl)methyl)-2-amino-1.10-phenanthroline(dppmaphen)by assembling the light-active 1,10-phenanthroline molecule with strong doner-PPh2 group,and prepared its Co(II)and Ni(?)complexes.The performances of these complexes toward the photoenhanced electrocatalytic hydrogen evolution reactions were investigated afterward.This dissertation mainly includes:1.A minireview on the applications of non-noble metal complexes in the electrocatalytic water splitting hydrogen evolution reactions.2.Reactions of dppmaphen with Co(?)and Ni(?)salts resulted in two mononuclear complexes[Co(dppmaphen)2(NO3)2](1)and[Ni(dppmaphen)2Cl]Cl(2).These two complexes were employed in catalyzing the electro HER reactions in basic(1.0 M KOH)media.The overpotentials(?10)were 430 mV(1)and 364 mV(2),and reduced to 345 mV(1)and 284 mV(2)under Xe light irridation,respectively.The Tafel slopes,electrochemical independence spectroscopies,and long-term stabilities of both catalysts were measured,while density function theory(DFT)calculations on the frontier orbitals were performed to explain the differences between the two compounds.In addition,the photocurrent responses of the two catalysts were also tested to demonstrate the effects of light on their catalytic activities.3.Compounds 1 and 2 were used as thermal decomposition precursors for the formation of nano-metal containing N/P doping graphene materials.The electrocatalytic HER and oxygen evolution reaction(OER)activities of the resulted materials in aqueous media were measured.Although the products didn't show outstanding performances,the methodology to prepare the doped graphene materials by direct treating the metal/N/P containing complex expressed herein is still worthy for reference.