Synthesis And Research Of Nickel Based Transition Metal Electrocatalysts For Oxygen Evolution Reaction

With the ever-increasing global energy demand and its associated environmental pollution,it is of vital importance to develop sustainable and renewable energy to replace traditional fossil fuel.Hydrogen has been considered as one of the most promising energy candidate to satisfy the requirement for future energy economy due to its high energy density and environmental friendliness.Among various hydrogen generation technologies,electrochemical water splitting,including cathodic hydrogen evolution reaction（HER）and anodic oxygen evolution reaction（OER）,has proven to be the most promising way to generate hydrogen with high purity.Compared with HER,the reaction kinetic of OER is more sluggish resulting from its four-electron transfer process,which severely hinders the efficiency of overall water splitting.Therefore,developing efficient and cost-effective OER catalysts is critical for scalable hydrogen production.Based on the above background,the specific research contents are as follows:1.Fe and P dual-doped nickel carbonate hydroxide/carbon nanotubes（Fe,P-NiCH/CNTs）hybrid electrocatalyst were fabricated through a solvothermal method.By virtue of the optimized electronic structure,improved conductivity and enriched active sites,the as-fabricated Fe,P-NiCH/CNTs hybrid electrocatalyst exhibits superior OER activity,with a low overpotential of 222 mV at 20 mA cm^-2 Moreover,The potential of Fe,P-NiCH/CNTs maintain highly stable with a slightly increased after continuous operation of 30 h,revealing its robust durability.Theoretical calculations reveal that the doped Fe and surface adsorbed PO₄^3-can regulate the electronic structure of evolved NiOOH and decrease the energy barrier of the rate-determining step,thus leading to the improved OER activity.2.Fe-doped Ni₅P₄（Fe-Ni₅P₄）nanoparticles were fabricated through simple salt template method and subsequent phosphidization treatment,which can act as catalysts for OER.The experimental results confirmed that doping of Fe can significantly enhance OER activity of Ni₅P₄.As a result,the optimized Fe-Ni₅P₄displays excellent OER activity with an overpotential of 271 mV to deliver 20 mA cm^-2 current density,which is obviously lower than that of IrO₂.The aforementioned results confirm its potential as highly efficient OER electrocatalyst.