Syntheses Of Functionalized Titanium-Oxo Clusters And Their Applications In Photoelectrochemistry And Separator Electrochemistry

Titanium-Oxo clusters with two or more metal Ti atoms are connected by organic ligands.Since titanium-Oxo clusters with clear molecular formulas and uniform size,they can exhibit promising applications in catalysis,biology,sensing and energy devices.Recently,scientists are gradually beginning to focus on the synthesis and the properties of titanium-Oxo clusters.However,the previous report of synthesized titanium-Oxo clusters-based composite materials is very rare.More importantly,researcher have hardly conducted extensive and in-depth studies on their applications in photoelectrochemistry and separator electrochemistry.At present,although,synthesis of titanium-Oxo cluster-based nanocomposite is the most effective strategy to enhance the photoelectrochemical performance of titanium-Oxo clusters,it still has some problems,such as unmatched energy band,weak contact and thick layer of titanium-based materials.Synthesizing inorganic-organic hybrid polymer electrolyte separator with titanium-Oxo cluster is the best way to improve electrochemical performance by enhancing the mechanical strength of polymer electrolyte separator.However,it also has some other problems.For example,poor dispersion of nanoparticle leads to their agglomeration in polymer electrolyte separator causing low mechanical strength.Titanium-Oxo cluster-based nanocomposite with above disadvantages was limited to their application in photoelectrochemistry and separator electrochemistry.In this thesis,a series of titanium-Oxo cluster-based nanocomposite have been synthesized through a new strategy.The monolayer cluster/BiVO₄ heterojunctions constructed,by functionalized titanium-Oxo cluster and BiVO₄ with energy-matching and intimate contacted interface enhance the performance of photoelectrocatalytic water-splitting.Hyperbranched-network polymer with uniform dispersion for highly mechanical strength can be obtained by polymerization of titanium-Oxo cluster,which has been applicated to polymer electrolyte in lithium ion baterries.According to design of the unique and functional titanium-Oxo clusters,this thesis studies systematically synthetic strategy and application of functional titanium-Oxo clusters and their nanocomposite in photoelectrochemistry and separator electrochemistry.The chapter one:firstly,the development and classification of functionalized titanium-Oxo clusters are briefly introduced and their application in photocatalysis and photocurrent response in recent years.The application and classification of titanium-Oxo clusters-based nanocomposite are summarized by previously reported.The synthentic strategy of nanocomposite is introduced.The application of titanium-Oxo cluster-based nanocomposite polymer eletrolytes in lithium batteries is also summarized.Finally,the main results and advantages in this thesis are showed as followed.The chapter two:a novel series of amino-modified Tis clusters with asymmetrical structure have been synthesized in situ solvothermal throught introducing aminobenzoic acid and benzenephosphonic acid.Tis clusters and BiVO₄ were combined to present a well-defined monolayer Tis clusters/BiVO₄ heterostructure with intimate interaction via a facile hydrolysis self-assembly strategy.Tis clusters/BiVO₄ nanocomposite led to significantly enhanced performance of photoelectrochemical water-splitting,which ascribed to M-O-Ti bonding at Ti5 clusters/BiVO₄ interface,energy-matching of nanocomposite and a well-defined monolayer Tis clusters on surface of BiVO₄.It is anticipated that this work could boost new insights for bonding mode between BiVO₄/cluster nanocomposites and the transfering of electron-hole pairs in photoelectrocatalysis at the molecular level.The chapter three:a novel series of functionalized titanium-Oxo clusters were synthesized in situ solvothermal throught introducing aminobenzoic acid and ethylene glycol.Introducing aminobenzoic into titanium-Oxo cluster show significant influence on their adsorption extended from the ultraviolet to the visible region.The photocurret response of functionalized titanium-Oxo cluster is significantly improved.Furthermore,the functionalized titanium-Oxo cluster was modifying hydroxyl groups with number of 16 on the surface.Therefore,synthesis of hyperbranched-network polymer electrolyte with uniform dispersion for highly mechanical strength by polymerization of titanium-Oxo clusters.The advantages of inorganic-organic hybrid polymer with titanium-Oxo cluster as eletrolytes in lithium batteries are highly ionic conductive and preventing lithium dendrites.The chapter four summarizes the work of this thesis.Challenges and prospects for the application of titanium-Oxo clusters nanocomposites in photoelectrocatalysis and Lithium ion batteries are also summarized.