Synthesis Of Cobalt-based Nanostructured Material And And Their Application In Electrocatalytic Oxygen Evolution Reaction

As a promising substitute for fossil fuels,hydrogen(H₂)has emerged as a clean and renewable energy.A key challenge is the efcient production of hydrogen to meet the commercial-scale demand of hydrogen.However,the high cost and low efficiency of the catalysts for cathode and anode in water splitting device remain the most knotty obstacle that needs to be stepped over.Water splitting electrolysis is a promising pathway to achieve the efcient hydrogen production in terms of energy conversion and storage in which catalysis or electrocatalysis plays a critical role.As a key half-reaction of electricity-driven water splitting,the oxygen evolution reaction(OER)is a sluggish process due to the transfer of four protons and four electrons.The optimal electrocatalysts can lower the energy costs required for water splitting via the reduced overpotential.Therefore,development of low-cost and robust OER electrocatalysts is of great importance for improving the efficiency of water splitting.Cobalt(Co)-based electrocatalysts have been widely applied as electrocatalysts for OER in water splitting.This article mainly studies the preparation of cobalt-based nanomaterials and their application in electrocatalytic oxygen production.The main findings are as follows:1.We prepare cobalt-modified honeycomb carbon nanofibers(Co-N-C)by electrospinning.The Co-N-C/CF is an oxygen evolution electrocatalyst with high catalytic activity and durability.In 1.0 M KOH,when the current density approaches 10m A/cm².Only 370 m V of overpotential is required.Notably,Co-N-C/CF also shows excellent electrochemical stability.2.We describe the development of CuO@Zn Co-LDH core-shell heterostructured nanowire array on copper foil(CuO@Zn Co LDH/CF)as an efficient water oxidation catalysts in alkaline media.Such CuO@Zn Co LDH/CF only requires overpotential of270 m V to achieve 10 m A cm^-2 in 1.0 M KOH,which is 110 m V less than that for Zn Co LDH/CF.Notably,this 3D catalyst electrode also demonstrates excellent long-term electrochemical durability.3.We synthesize Co-MOF/NF nanosheet array precursor on nickel foam by hydrothermal method,and then electrodeposite Zn Co-layered double hydroxidedouble to form Co-MOF@Zn Co LDH/NF heterostructure nanoarray.The prepared Co-MOF@Zn Co LDH/NF shows superior water oxidation activity.Merely 260 m V of overpotential is needed in 1.0 M KOH solution to achieve j=20 m A cm^-2 in 1.0 M KOH.And the Tafel slope is as low as 82 m V dec^-1.It is worth noting that it also exhibits high long-term electrochemical durability,and its catalytic activity can be maintained for at least 24 hours.