首页|Regulating the Photoisomerization of Covalent Organic Frame-work for Enhanced Photocatalytic Hydrogen Evolution
Regulating the Photoisomerization of Covalent Organic Frame-work for Enhanced Photocatalytic Hydrogen Evolution
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
万方数据
Covalent organic framework(COF)is a desirable platform to tailor electronic properties for improving photocatalytic performances.However,the study on excited-state configurations that determine photogenerated carrier dynamics has long been neglected.Herein,we concentrate on the molecular design of β-ketoenamine-linked COFs to drive their photoisomerization via the excited-state in-tra-molecular proton transfer(ESIPT),which can induce the partial keto-to-enol tautomerization and accordingly rearrange the pho-toinduced charge distribution.We demonstrate that the push-pull electronic effect of functional side groups attached on the frame-work linkers is directly correlated with the ESIPT process.The phenylene linkers modified with electron-withdrawing cyano-groups re-inforce the ESIPT-induced tautomerization,leading to the in situ partial enolization for extended n-conjugation and rearranged elec-tron-hole distribution.In contrast,the electron-rich linkers limit the photoisomerization of COF and suppress the photoinduced elec-tron accumulation.Thus,the maximum hydrogen evolution rate is achieved by the cyano-modified COF,reaching as high as 162.72 mmol·g-1·h-1 with an apparent quantum efficiency of 13.44％at 475 nm,which is almost 11.5-fold higher than those of analogous COFs with electron-rich linkers.Our work opens up an avenue to control over the excited-state structure transformation for enhanced photochemical applications.
万方数据
