Controllable Preparation Oxygen Evolution Reaction Properties Of Several Nano Electrocatalysts

It's considered to be one of the best source to replace fossil fuels,which is Hydrogen,a rich,renewable,clean new energy source.One of important way to make hydrogen is water electrolysis,with this way can make Hydrogen has much high purity,controlled the Hydrogen production automatically,and no pollution.The process is also simple and easy to maintain.However,an excessively high anodic oxygen evolution reaction overpotential severely reduces its electrical energy utilization,so the water electrolysis industry development was limited.Therefore,it has decisive significance for the water electrolysis industry development to find a high-efficiency oxygen evolution reaction electrocatalytic material which can effectively reduce the overpotential of oxygen evolution reaction and improve the power utilization rate with appropriate price.Noble metals and transition metal compounds have excellent capacity in oxygen evolution reaction?OER?,so it is a hotspots research in oxygen evolution electrode materials currently.Therefore,the purpose of this thesis is to make novel low-noble metal composite material,transition metal compound with high specific surface area,and its composite material by a simple method.What the thesis do research about as following:?1?First,adopt chemical vapor deposition to make nitrogen-doped carbon nanotubes?CN_xNTs?as a substrate material.Then,get the composite catalysts IrO_x/CN_xNTs by solvothermal method.Do research the effects of different IrO_x loadings on their electrocatalytic OER properties in neutral solution?0.1 M KHCO₃?.The results show that IrO_x nanoparticles were uniformly dispersed in CN_xNTs,and the obtained IrO_x/CN_xNTs catalysts exhibited good OER electrocatalytic activity in CO₂saturated 0.1 M KHCO₃ solution.15-Ir/C is the most suitable catalyst,when the current densities of 1 and 10 mA cm^-2,the lowest overpotentials of 171 and 472 mV.However,8-Ir/C show the highest mass activity(0.097 mA?g^-1Ir).In short,less loading of noble metal iridium will greatly improve the capacity of CN_xNTs catalysts in oxygen evolution reaction.The obtained composite catalyst can successfully applied in neutral media and present good oxygen evolution reaction capacity.?2?Get the urchin-like Co₃O₄,Co₃O₄ nanosheets,Co₃O₄ nanoparticles and Co₃O₄nanospheres,by hydrothermal method and annealing treatment.Do study for the effects of different morphology of Co₃O₄ materials on their OER electrocatalytic activity.The results showed that the urchin-like Co₃O₄ exhibited the best oxygen evolution reaction?OER?catalytic capacity in the four different morphologies of Co₃O₄ catalysts.At the current density of 10 mA cm^-2,urchin-like Co₃O₄ exhibited a low overpotential of 308 mV and a small Tafel slope of 72 mV dec^-1,which indicates its superior oxygen evolution reaction catalytic capacity.The mechanism research results in this work showed that the electron transfer method of Co₃O₄-1 is a two-step process,in which the peroxo species(OOH^ads)is the intermediate.?3?The One-dimensional NiCo₂O₄ nanowires and honeycomb-like two-dimensional NiCo₂O₄ materials which gained by hydrothermal and electrodeposition annealed separately.Combining the two method and get a simple two-step wet chemical method,which can developed three-dimensional?3 D?NiCo₂O₄ layered nanostructures on rigid conductive carbon fibers.Do research apartly three NiCo₂O₄/C materials effect on the electrocatalytic activity of oxygen evolution reaction.It show that among the three different NiCo₂O₄/C catalysts,3 D layered nanostructured NiCo₂O₄ composite catalyst exhibits the best oxygen evolution reaction?OER?catalytic capacity.At the current density of 10 mA cm^-2,the lowest overpotential was330 mV.The high-capacity nanocomposite catalyst gained by the two-step wet chemical method which using carbon cloth as a base material,provide new thought and method for the development of oxygen evolution reaction materials.