Interface Regulation Of Non-noble Metal Based Electrocatalysts For Oxygen Evolution Reaction

The contemporary society has been advanced by fossil fuels,but a series of problems have been resulted from its pollution and non-renewable.Thus,renewable green energy meets people’s demand for alternative energy.Due to its unique advantages over other energy sources,hydrogen energy has become an ideal substitution for fossil fuels.Water electrolysis is a currently feasible approach of industrial hydrogen production.The combination with renewable energy generation technologies such as solar energy and wind energy,maintains the advantages of green sustainability,which is significant to the sustainable development strategy.Due to four electron transfer processes,oxygen evolution reaction involves more sluggish kinetics and limits the efficiency of hydrogen production.OER electrocatalyst plays an important role.Compared with precious metal-based electrocatalysts,high-abundance and low-cost transition metal materials obviously have broad development in electrocatalysis.The electrocatalytic gap between transition metal and precious metal materials can be completely filled by various strategies.In this paper,Three types of transition metal-based electrocatalytic materials based on the interface engineering are fabricated as the following:（1）The Ni-Co-based precursor sheet-like arrays were constructed in situ on the Ti mesh by the solvothermal method,and subsequently converted into the spinel structural NiCo₂O₄by low-temperature calcination.This study showed that the self-supported electrode NiCo₂O₄/Ti performed great electrocatalytic performance in an alkaline electrolyte.A current density of 10 m A cm^-2was delivered at overpotentials as low as353 m V.Besides,the current only decreased by 6%after 20 hours’operation.The strongly coupled interfacial effect between the carriers and the active sites promotes and accelerates electron transport,thus improving the catalytic performance.（2）A composite of NiV-LDH and FeOOH was constructed in situ on the Nifoam through a facile two-step method,containing hydrothermal method and ultrafast interfacial reaction process.Experimental analysis showed that the NiV-LDH@FeOOH/NF electrode demonstrated remarkable OER activity in alkaline medium,which required an overpotential of 297 m V to drive the current density of 100 m A cm^-2.Moreover,the electrode still maintained 95%of the initial catalytic activity in alkaline medium for 20 h.The nanoscale heterostructure was constructed by the combination of NiV-LDH nanosheets and FeOOH nanospindles,thus producing a strong coupling effect.The activity of catalyst was improved by interfacial active sites through interface engineering.（3）The 3D core-shell nanostructure was fabricated by a series of successive procedures.NiMo O₄nanowires grew directly onto the Nifoam by the hydrothermal method,and subsequently converted into NiMoP nanowires in the phosphorisation process.Eventually,the surface of the NiMoP nanowires was loaded with NiFe-LDH nanosheets by electrodeposition.The resulting heterostructured NiMoP@NiFe-LDH exhibited remarkable catalytic performance with an ultralow overpotential of only 299m V at a current density of 150 m A cm^-2and a Tafel slope of 23.3 m V dec^-1in alkaline medium.Moreover,the catalytic activity of the electrode was decayed less after long-running.The optimization of the electronic structure at the nanointerfaces of the heterojunction reduces the energy barrier of the catalytic process,thus improving the efficiency and stability of the OER electrocatalyst.