Performance Engineering Of Electrocatalysts Derived From MOFs

In recent years,the production of hydrogen through water electrolysis using renewable energy sources such as solar,wind,and tidal power has attracted significant attention due to hydrogen’s characteristics as a green,efficient,and pollution-free secondary energy source.However,the application of noble metal catalysts in water electrolysis technology hinders the widespread application of this method for hydrogen production.To solve this issue,it is necessary to explore friendly and efficient catalysts to promote the development of water splitting technology.Metal-organic frameworks（MOFs）have the potential to be electrocatalyst/electrocatalyst precursor originating from the merit of the tunable composition and various morphology.In this thesis,MOFs,and their derivatives such as phosphides and selenides,were synthesized using the dithiooxamide（DTO）as ligand together with hydroxide or metal ions as templates and metal sources.The influence of the morphology,electronic structure and heterostructure composition on catalytic performance was investigated.Firstly,a 1D-2D nanowire array of Ni-MOF was synthesized using Ni（OH）₂ as a template and metal source,which was found to be an efficient and durable catalyst for whole water splitting under alkaline conditions.The Ni-DTO electrocatalyst achieved a current density of 10 m A cm^-2 at only 1.61 V in a 1 M KOH solution,and exhibited good stability.Secondly,a dual-ligand MOF-derived phosphide heterostructure Co_1.94P/Ni₂P,was synthesized using DTO and dimethylimidazole as ligands and CoNi hydroxide nanowires as precursors.The material displayed excellent HER and OER performance due to the introduction of dual ligands,which increased the defect density.To drive the current density of 10 m A cm^-2,it was needed 70 m V and 265 m V for HER and OER,respectively.As a full water electrolysis electrocatalyst,it required only 1.57 V to achieve 10 m A cm^-2 in a 1 M KOH solution.Thirdly,a CoCu-MOF-derived selenide heterostructure electrocatalyst（D-CoCuSe）was synthesized,then,trace amount of Pd nanoparticle was introduced into the D-CoCuSe to form the D-CoCuSe-Pd composite material for improving the activity further.Thanks to the synergistic effect of the heterojunction structure and Pd nanoparticles,the optimized D-CoCuSe-Pd catalyst exhibited excellent HER and OER performance in an alkaline medium.As a result,as bifunctional electrocatalyst,D-CoCuSe-Pd provided a current density of 10m A cm^-2 at only 1.59 V.