Ultrasensitive photochromism and impedance dual response to weak visible light by solvated Pb(Ⅱ) modified polyoxomolybdate  

作　　者：Jiayuan Zhang Xinyu Wang Gui Wang Yi Feng Chunhui Zhang Tao Pang Guanggang Gao Linlin Fan Hong Liu 

机构地区：[1]School of Materials Science and Engineering,University of Jinan,Jinan 250022,China [2]College of Pharmacy,Jiamusi University,Jiamusi 154007,China

出　　处：《Chinese Chemical Letters》2023年第2期567-571,共5页中国化学快报（英文版）

基　　金：the financial support from the National Natural Science Foundation of China (No. 21971085);the Natural Science Foundation of Shandong Province (No. ZR2019MB004)。

摘　　要：Polyoxometalates (POMs) are important inorganic photochromic materials to be potentially applied in photo-induced switch,energy storage,and even the detection of light.However,due to the limited sensitivity of POMs,it is difficult to realize the photochromic response to weak visible light.In this paper,by the coordination of solvated Pb(Ⅱ),a new structure-defined chain-like polyoxomolybdate complex of[(Pb(DMF)_(4))^(3)(P_(2)Mo_(18)O_(62))_(2)]n(Pb_(3)Mo_(18) ,DMF=dimethylformamide) has been demonstrated by a facile solvent-diffusion approach.By virtue of interactions between Pb(DMF)_(4) and polyoxoanions,Pb_(3)Mo_(18) shows an ultrasensitive photochromic response to weak visible lights and forms the reduced’heteropoly blue’species through ligand-to-metal charge transfer (LMCT) process.A new mechanism is firstly proposed here that the 6s orbital lone electron pair on Pb(II) can effectively stabilize the generated hole of oxygen atoms as a result of O→Mo charge transfer.Through the proposed mechanism,the LMCT barrier is drastically lowered and allows the coloration to be occurred even upon weak visible light.Also,because the conductivity of Pb_(3)Mo_(18) enhances with the increase of reduction extent,its electrochemical impedance signals are proportionally response to irradiation intensity.Especially,for the first time,the polyoxomolybdate composite can be used to detect weak visible light,in which the optical signal can be converted into electrical signal output.Moreover,Pb_(3)Mo_(18) can be drip-coated on the surface of the screen printed chip electrode,which is facile to the detection of light by portable devices compatible with computers,mobile phones and other electronic equipment.This work not only highlights a new approach to the molecular design of photochromic POMs by the coordination of metal ions with the effect of inert electron pair,but also lays a foundation to extend the application of POMs as light signal sensors.

关 键 词：PHOTOCHROMISM POLYOXOMETALATE IMPEDANCE Visible light Screen printed chip 

分 类 号：TB34[一般工业技术—材料科学与工程]