Nickel-Iron Layered Double Hydroxide@ZnO For Highly Efficient Oxygen Evolution Reaction

With the improvement of science and the continuous increase of the global population,the exploitation and utilization of fossil fuels have increased year by year,which has caused a series of energy and environmental problems.Especially for the using of traditional energies,a large amount of carbon emissions caused serious environmental problems,such as climate warming,sea level rising and so on.Therefore,finding environmentally friendly and renewable new energy sources has become one of the major challenges for mankind in the 21st century.Hydrogen energy has gradually received attentions due to its advantages like clean,high-efficiency,and recyclability.In addition,hydrogen is also an crucial chemical raw material and is widely used in numerous fields.Hydrogen production by electrolysis of water is an typical production method.The production method has been maturely applied to industrial production because of the simple equipments,easily available raw materials,and the high purification of hydrogen.However,due to the high electrical energy required for the reaction and the expensive electrode catalysts,the cost of hydrogen production remains high.At present,the electrode materials for electrolyzed water are still mainly precious metals Pt(cathode)and RuO2 or IrO2(anode).The oxygen evolution reaction occurs at the anode,but its slow kinetics severely restricts the efficiency of water electrolysis.Therefore,the development of cheap,high-performance,and stable oxygen evolution reaction catalysts has become one of the important issues in this field.This paper mainly discussed the design and preparation of high-efficiency catalysts for oxygen evolution reaction in the electrocatalytic water splitting process by transition metal Ni under alkaline conditions.The main research contents and results are as follows:(1)The Ni-Fe LDH@ZnO/NF material was designed and synthesized based on the wet-chemical route.The specific surface area and stability of the material were increased by introducing ZnO rods as the support material of Ni-Fe LDH.The catalytic performance of the material was improved after modification.Ni-Fe LDH@ZnO/NF exhibited excellent OER performance with an overpotential of 271 mV at a current density of 10 mA·cm-2,as well as long-term stability up to 29 h.(2)Through in-situ Raman characterization,the cataly tic mechanism of the active material Ni-Fe LDH was analyzed.It also verified that adding a small amount of Fe could effectively enhanced the performance of the material.Thi work provided a basis for the subsequent design.and synthesis of an electrocatalytic oxygen evolution reaction catalyst.