Design And Properties Study Of Metal Ions-regulated MOFs-based Triboelectric Materials

As a new type of energy collection technology,triboelectric nanogenerator（TENG）can effectively alleviate the current pressure of energy and environment.In recent years,metal organic frame materials（MOFs）have been introduced into the field of triboelectric materials due to their diverse structures,ease of customization,and excellent performance.However,few people have studied the specific influencing factors and theoretical discussions of the structure of MOFs on triboelectric materials.This paper is divided into three systems,fully studying the relationship between metal ions in MOFs and performance of triboelectric nanogenerator,providing theoretical guidelines and basis for the synthesis of high-performance triboelectric materials in top-level design.In terms of practical application value,the MOFs based triboelectric nanogenerator as an external power source can effectively prevent metal corrosion and power micro capacitors,and can easily light up a large number of commercial LED lights,which opens up new ideas for further commercial applications of functional MOFs-TENG.（1）The method of central metal ion exchange was used to improve the output performance of MOFs based triboelectric materials.A batch of isomorphic MOFs were obtained by solvent assisted metal ion exchange（SAME）,and the electronic structure in the secondary building units was affected by adjusting the changes of metal ions in the center of the MOFs,thereby regulating the triboelectric behavior.Among them,the triboelectric nanogenerator assembled with ZUT-75（Co）achieved ultra-high output performance.Finally,it was found that the lower degree of metal ion coupling within MOFs leads to a higher probability of electron escape,thereby stimulating more triboelectric electrons.（2）The relationship between the magnetic behavior of MOFs and the triboelectric current effect was studied.By adjusting the type of metal ions(Zn²⁺,Ni²⁺,Co²⁺),the number of metal center spins was significantly increased,and the magnetic behavior was successfully adjusted,resulting in geometric changes in the electronic environment of the secondary building unit（SBUs）.The results showed that adjusting the type of metal and increasing the spin number of the metal center could significantly enhance the electron delocalization effect and effectively improve the triboelectric behavior of MOFs.This work not only proved that metal organic chains were effective materials for improving TENG performance,but also proposed a magnetization current coupling theory,which effectively complemented the theoretical system of triboelectric nanogenerators.（3）A double helix metal organic framework（ZUT-8s）was synthesized using chiral square acid ligands for the first time,and the organic linkers therein were changed to obtain three isomorphic but different conjugated metal organic chains.The test results showed that metal organic chains with higher conjugation degree behaved higher triboelectric output performance.This is mainly because enhancing the conjugation effect of metal organic chains can significantly reduce the band gap and effectively improve output performance.In addition,under the stimulation of light,the triboelectric current effect of all ZUT-8s was significantly improved.This indicated that conjugated MOFs materials could absorb photon energy,thereby generating more triboelectric electrons.