Hierarchical Structure Construction And Properties Of Nickel-based Electrocatalysts

Hydrogen production technology from water electrolysis has attracted much attention due to its cleanness and environmental protection,sufficient raw materials and simple process.However,due to the slow kinetics of the anode reaction and the high cost of noble metal catalysts,it is difficult to achieve large-scale industrial production.Nickel-based compounds can be used as more economical and efficient electrocatalysts due to their abundant reserves and tunable valence states,but they often suffer from poor electrical conductivity and low intrinsic activity.Therefore,in view of the above problems,this paper selects Ni-based hierarchical electrocatalysts as the research object,and constructs two nickel-based nanomaterials with special morphologies and components by adjusting the microscopic morphology and electronic structure.appearance and electrocatalytic performance.And a high-efficiency hydrogen production platform was built using chemical-assisted hydrogen production technology.The main research contents are as follows:1.A series of Ni/Ti N/CC hierarchical structure catalysts were prepared.The carbon layer-coated nickel clusters are dispersed on the titanium nitride nanowires in a"rhizobia"shape.The active site exhibits excellent electrical conductivity,catalytic activity,and stability:In alkaline media,an oxygen evolution current density of 10m A cm^-2can be achieved with only an overpotential of 363 m V,the initial activity can be maintained for at least 24 h at the current density of 30 m A cm^-2.2.A series of Ni₃N_1-x@CC catalysts were prepared by a combination of solution method and vapor deposition method to control the number of nitrogen vacancies in Ni N nanosheets.Its"coral-like"nanosheet array provides a large specific surface area,the introduction of nitrogen ions improves the electronic structure of nickel metal,and the local electron density is further regulated by the construction of nitrogen vacancies,which makes the catalyst exhibit high catalytic activity and long life.Catalytic stability over time.Benefiting from the unique electronic structure,the Ni₃N_1-x-3@CC catalyst can achieve a current density of 10 m A cm^-2at only 1.67 V under the OER/HER（oxygen evolution reaction/hydrogen evolution reaction）full reaction,and at Maintain stability for at least 24 h in an alkaline environment.3.In order to further improve the hydrogen evolution efficiency and reduce the overall hydrogen production energy consumption,a full reaction MOR/HER（methanol oxidation reaction/hydrogen evolution reaction）was designed to replace the OER/HER,and the Ni₃N_1-x-3@CC catalyst performed High catalytic activity(only1.589 V for 10 m A cm^-2),and good stability,only 8%current density loss in 24 h in the MOR/HER.