Synthesis Of Non-Precious Metal Nanomaterials And Their Electrocatalytic Properties For Water Splitting

Non-precious metal nanomaterials,with the metrits ofearth-abundant,low cost and good electrocatalytic activity,are considered as one of the most promising catalysts for electrocatalytic water splitting.Although the non-precious metal nanomaterials have developed rapidly in recent decades,their current activity and stability can not meet the commercialization requirements of electrocatalytic water splitting.In order to further improve the OER activity of non-precious metal nanomaterials,this paper intends to improve its catalytic performance by fine regulation of its active area,electron conduction and Gibbs free energy.Specific strategies include:(1)Increasing the active area,providing more exposed active sites,and thereby enhancing catalytic activity;(2)Enhancing the conduction performance of material electrons,accelerating the electron transfer process,thus accelerating the reaction;(3)Optimizing the ?G of the catalyst could fundamentally hasten the reaction kinetics.Although some research progress has been made about these kinds of regulation methods,it still needs to further expand the regulation strategy and provide more effective regulation methods.Therefore,it is very value and significance to study the active area,electron conduction and Gibbs free energy regulation for the development of high activity non-precious metal nanomaterials.In this thesis,we have developed in-situ growth of three dimensional(3D)NiFe-LDH@CNT nanosheets,NiCe@CP nanosheets with many hydroxide-oxide interfaces and Fe2P2O7&Co2P2O7@N-doped carbon core-shell structure materials to fine regulating their active area,electron conduction and Gibbs free energy.The morphology,structure and catalytic properties of these synthetic materials are investigated.The main contents are as follows:Chapter 1.In this thsis,the progress of non-precious metalnanomaterials,the OER mechanism,the evaluation method of activity performance and the improvement strategies of electrocatalytic performance were briefly introduced.And the basis and research content were illustrated in this chapter.Chapter 2.The iron doped hydroxide nanoparticles were in-situ grown on the conductive carbon nanotube carrier to form a 3D structure nanomaterial.Large specific surface area,good conductivity,easy electrolytic diffusion of 3D structure and strong electron interactions between elements Ni and Fe make the optimization component NigFe1-LDH @CNT exhibit high OER activity and stability.Chapter 3.The Ni(OH)2 nanosheets containing Ce is in situ grown on the carbon paper,forming the 3D structure material NiCe@CP with a large number of hydroxide and oxide interfaces.The interface effect between Ni(OH)2 and CeO2 can regulate the Gibbs free energy of OER intermediates on the surface of the material,which make the optimization component Ni4Ce1@CP exihibit high OER andoverall water splitting activity and stability.Chapter 4.We demonstratea facile and easy operating method to development a series of carbon coated bimetal Fe/Co phosphate nanomaterial catalysts.Benefit fromthe nitrogen-doped carbon and the strong electronic effect between metal elements Fe/Co,the optimization component N-C@(Fe4Co1)P2O7 exhibit high OER and overall water splitting activity and stability.