Research On Porous Treatment And Electrolytic Water Properties Of Cobalt-Iron Alloy Electrode And Nickel Current Collector

With the development of the era,the human needs for clean energy are getting higher and higher,and the electrocatalytic water splitting to produce hydrogen is a research hotspot in the field of energy storage.As the four half reactions of water decomposition,Oxygen Evolution Reaction?OER?and Hydrogen Evolution Reaction?HER?are the key factors influencing the production of Hydrogen by water splitting,which have such problems as kinetic inertia,high electrocatalytic overpotential and large amount of energy required for chemical bond decomposition.Therefore,the development of efficient,inexpensive OER and HER catalytic electrodes is an important research direction in the field of electrolytic water to produce hydrogen.At present,many researches on electrocatalytic water splitting focus on the optimization of catalysts,but ignore the effect of current collector microstructure on electrocatalytic water splitting.In this paper,the efficient porous of commercial Co-Fe alloy is realized through a simple oxidation-reduction process,which utilizes the expansion and contraction mechanism of metal.The effects of oxidation and reduction temperature and time on the porous structure of Co-Fe alloy were investigated.By optimizing the preparation parameters,a highly efficient porous Co-Fe water splitting electrode was prepared.The specific surface area of the electrode catalysis process was greatly increased by the porous treatment,among which the study showed that the double-layer capacitance of micro/nano porous Co-Fe alloy was increased by several times to dozens of times compared with the untreated Co-Fe alloy.Where the micro/nano porous Co-Fe alloy was used as OER electrode,the overpotential at the current density of 10 m A cm^-2was 287.3 m V,which decreased by 78 m V?21%?compared with 365.3 m V of the untreated Co-Fe alloy.Meanwhile,the overpotential of the micro/nano porous Co-Fe alloy as HER electrode at the current density of10m A cm^-2was 224.7 m V,which was 152.7 m V?40%?lower than 377.4 m V of the untreated Co-Fe alloy.In this paper,the microstructure of Nickel Foam?NF?current collector was modified by high-temperature oxidation-reduction method.After high-temperature oxidation-reduction,a large number of micro-porous structures appeared on the surface and inside of the ligaments of Nickel Foam current collector,forming Micro/nano Porous Nickel Foam?MPNF?.These pore structures can greatly improve the specific surface area of the current collector,thereby increasing the contact area between the current collector and the active substance,reducing the overpotential of the composite electrode,and significantly improving the catalytic performance of the composite electrode.Then?-Mn O₂and?-Co?OH?₂were prepared on the surface of nickel collecting fluid by electrochemical deposition to construct OER composite electrodes respectively.The results showed that the two composite electrodes with the NF current collector after porous treatment showed better OER catalytic performance,including the overpotential of MPNF/?-Mn O₂at the current density of 10m A cm^-2was 363.5 m V which decreased by 66.4 m V?15%?compared with 429.9 m V of NF/?-Mn O₂.The overpotential of MPNF/?-Co?OH?₂at the current density of 10 m A cm^-2was 274.6 m V,which was 47.7 m V?15%?lower than 322.3 m V of NF/?-Co?OH?₂.More importantly,the porous structure enhances the adhesion between the active material and the current collector,thus improving the stability of the composite electrode.