Study On Morphology Control And Electrocatalytic Properties Of Ruthenium-Based Nanomaterials

Noble metal materials are widely used in fuel cell reactions and chemical conversion because of their high catalytic activity.However,due to the high price of precious metal materials,how to use precious metals efficiently has become a difficult problem to overcome.The results show that the catalytic performance of nanomaterials is closely related to their composition,size and surface structure.Therefore,rational design of nanocrystalline nanostructures,formulation of effective synthesis strategies and improvement of catalytic performance of noble metals are effective ways to achieve effective utilization of noble metals.In order to further improve the catalytic activity of ruthenium-based nanomaterials,the catalytic performance of ruthenium-based nanomaterials was improved by fine regulation of their composition,size and surface structure.Specific strategies:(1)change the composition,reduce the amount of precious metals,regulate the relationship between metals,and improve the catalytic activity;(2)regulate the size of catalyst,increase the active sites,so as to accelerate the reaction rate;(3)regulate the surface structure of catalyst,change the surface structure,not only increase the active sites,reduce the adsorption energy on the catalyst surface,accelerate the reaction rate.Thereby,improve the catalytic activity of the catalyst.Although some progress has been made in these control strategies,few ruthenium-based nanomaterials have been applied to the total decomposition of water.Therefore,it is of great significance to improve the electrocatalytic activity of Ru-based nanomaterials by adjusting their morphology,composition,size and surface structure.In this paper,Ru-Ni NAs three-dimensional structural materials and Ru NWs and Ru NPs have been synthesized.The composition,size and surface structure of Ru-based nanomaterials have been controlled.The morphology,structure and catalytic properties of Ru-based nanomaterials have been characterized and studied in depth.The main contents are as follow:Chapter 1.Hydrogen evolution reaction(HER),oxygen evolution reaction(OER)reaction mechanism and performance evaluation methods are introduced.The research progress of ruthenium-based nanomaterials is briefly introduced,and the basis and content of this paper are expounded.Chapter 2.An effective wet chemical method was used to synthesize three-dimensional,multi-layer Ru-Ni nanosheets composed of ultra-thin nanosheets as monomers.Valence band spectra showed that the introduction of Ni reduced the d-band centers of Ru-Ni electrocatalysts and effectively regulated the surface electronic environment of hydrogen evolution reaction.A large amount of RuO2 is produced after air treatment at 350?,which provides abundant active sites for oxygen evolution reaction and explores their high performance of water decomposition under wide pH conditions.Chapter 3.A universal wet chemical method was used to synthesize nanowires of different metals.Different metals were induced to form nanowires by the introduction of lead.First-principles calculations show that the occurrence of Ru atom point defects on RuO2(200)facet will reduce OER overpotential,and the free energy of adsorption of OER intermediates will decrease due to the right shift of d-band center.Thus,the activity of OER was increased.Chapter 4.Through the addition of copper,Ru is regulated to form sheet structure.This sheet structure has the characteristics of ultra-thin and has a large number of pits on the surface.This pit can expose a large number of active sites and regulate the surface state by temperature treatment,thus improving the activity of OER.