Preparation Of MOFs And COFs Composites With Transition Metal Sulfides And Their Photocatalytic Hydrogen Evolution Properties

Energy and environment are the main focus of people’s attention at the stage of social development.At present,the main supply of energy required by people is still mainly from fossil fuels,such as coal,natural gas and petroleum,and these limited fossil fuel resources will cause great damage to the environment.Therefore,it is a great and arduous mission for contemporary researchers to research and develop low-cost,efficient,clean and sustainable energy.As a new clean energy,hydrogen energy is the most ideal substitute for traditional energy such as coal and petroleum.Photocatalytic aquatic hydrogen is the direct decomposition of water into hydrogen by solar energy.Compared with other hydrogen production systems,the main advantage of photocatalytic system is that the method is more convenient,economical and applicable.Transition metal sulfide is composed of transition metal and sulfur atom.Due to itsadjustable band gap,it has a good application prospect in optoelectronics and so on.Metal organic frameworks（MOFs）are crystalline porous materials composed of metal ions or clusters and organic ligands through coordinate bond.Based on its porous structure,large specific surface area and strong coordination structure,it has been widely studied in the fields of gas adsorption,drug carrier,photocatalysis and so on.Covalent organic frameworks（COFs）materials are mainly new porous materials formed by covalent bonding of H,B,C,N and o.Its structural characteristics are similar to MOFs,but its stability is much higher than MOFs.Therefore,as a new material,it is also widely studied in gas adsorption and catalysis.The work of this article mainly consist of the following two contents:（1）Preparation and photocatalytic hydrogen production of 1T-Mo S₂QDs@Composites.1T-Mo S₂QDs and Ui O-66 were successfully synthesized,and 1T-Mo S₂QDs were compounded with Ui O-66 through in-situ synthesis to form composites.Mo S₂quantum dots have three different phases:1T、2H and 3R.Compared with 2H-Mo S₂QDs and 3R-Mo S₂QDs,1T-Mo S₂QDs has higher conductivity and can more effectively increase the charge transfer between electrons.Therefore,the introduction of 1T-Mo S₂QDs can improve the electron transfer of Ui O-66 metal active center Zr,and improve the electronic migration of the composite and increase the photocatalytic hydrogen evolution performance of the composite because of the low electron band structure of transition metal sulfide.（2）Ni S@CTF-1 Preparation and photocatalytic properties of composites.We successfully synthesized CTF-1 and Ni S,and successfully loaded Ni S on CTF-1 to form composites.CTF series belongs to a kind of COFs.Based on the structural characteristics of COFs and theπconjugated cyclic aromatic ring of CTF-1,it is conducive to visible light absorption,and theπpiling composition is favorable to charge transfer.Therefore,CTF-1was introduced into the compose of Ni S.The results show that the hydrogen production performance can reach 65 mmol·g^-1,which can be compared with that of some precious metal containing materials.