Metal-based Functional Materials:Synthesis And Investigations Of Electrochemical And Transport Properties

Along with the progress of human civilization,large-scale development of industrial civilization and social civilization also make the energy problem become more and more rigorous.Which country can occupy the highland of energy technology in the future,it will certainly be able to occupy a favorable position in the competition for the right of speech in this world.On the one hand,searching for new renewable energy that can replace fossil fuels has become a hot research field.In that field,lithium ion batteries and electrocatalytic water splitting as two important ways of electrochemical energy storage and conversion,has been widely studied and reported by massive research groups and institutions around the world.On the other hand,superconducting research has attracted much attention in many countries.For example in the field of electric energy transportation,a significant amount of electric energy is consumed in the form of joule heat,due to the resistance of copper or aluminum wires.If the cable made of superconducting material,the energy consumption on the transmission line will be reduced to zero theoretically,and the economic benefits will be invaluable.In addition,superconductors have potential applications in the fields of new superconducting electronic devices,maglev trains,superconducting generators,controllable nuclear fusion and so on.If the exploration of superconducting materials in the future can reach the level of practicality and industrialization,it will certainly have a significant impact on the science and technology of modern civilization,and may even trigger a new round of industrial revolution.This paper aims to design and synthesize new functional materials based on the research of lithium ion battery,electrocatalytic water splitting and superconductor,so as to provide new research ideas and platforms for their practical applications.In general,the main content of this paper includes the following aspects:1.Designed a facile two-steps method of macro-quantity preparation for double-anion compound of FePS3@C nanocomposite,and studied its Li-storage properties as anode materials.Firstly ferrocene powder was loaded into a stainless steel autoclave,and heated at 973K to obtain Fe@C mixture.Then the FePS3@C sample was synthesized from stoichiometric mixtures of Fe@C,red phosphorus and sublimate sulphur in an evacuated quartz tube at 923K for 24h.As a novel anode material for Li-ion batteries,the FePS3@C nanocomposite exhibit a high capacity of 1000 mAh g-1 at a current density of 0.2 A g-1 and excellent reversibility over 100 cycles.2.Novel porous CoPS@C nanocomposite was successfully synthesized and its electrochemical properties were systematically tested.The performances of the CoPS@C electrode as a non-noble metal electrocatalyst for hydrogen evolution reaction?HER?and oxygen evolution reaction?OER?show good activity.On the other hand,the electrochemical investigation of CoPS system for lithium ion batteries?LIBs?is reported for the first time.The CoPS@C nanocomposite as a novel anode can maintain a capacity of about 713 mAh g-1 at a current density of 0.2 A g-1,indicating its potential applications in lithium storage.3.We developed a facile one-step method and successfully synthesized a series of carbon-coated germanium-based composites Ge@C,GeS@C and GeSe@C.As anode materials for lithium batteries,they all showed excellent properties.For example,GeSe@C composites exhibit a high capacity of nearly 780 mAh g-1 at a current density of 0.2 A g-1 and excellent reversibility over 180 cycles.This is an excellent Li-storage performance in the comparison of similar anode materials.4.A series of Pb-doped Bi-based alloys ?-Bi1-xPbxPd and ?-Bi2-xPbxPd were synthesized by facile solid-state method.The magnetic susceptibility and resistivity tests indicate that they were bulk superconductivity and superconducting temperature?Tc?gradually decreased with higher Pb content.On the other hand,Bi-doped Pb2-xBixPd alloys were also successfully prepared via solid-state method.It is found that superconducting T,is enhanced when Bi-doping content x=0.2 and 0.6,while T,is slightly suppressed when x= 0.4.The electronic structure calculations based on density functional theory?DFT?of Pb2Pd alloy are also presented in this paper,the energy bands across Fermi level with high dispersion indicates favorable electronic conductivity.One can see that the 6p orbital of Pb atoms and 4d orbital of Pd atoms contribute majority of states at the Fermi level.Besides,we have extended the synthesis of other noble metal based compounds,and have successfully prepared novel BiRh?PbPd₃ and Sn₂Pd.