本文要点：
在这项工作中，作者设计并合成了sp2C连接的COF，命名为DPP-COF(图1a)，其中DPP和三嗪连接物充当受体，噻吩充当供体。这种COF表现出接近1200 nm的宽吸收范围和1.06 eV的超窄带隙，因此它是带隙最小的COFs之一。
DPP-COF在酸和碱溶液中都显示出高的化学稳定性，并显示出显著的光电流响应特性。此外，这种COF被引入到硫化物和四氢异喹啉的光氧化反应中，表现出优异的光催化活性，产率在87%到95%之间。
在反应过程中观察到单线态氧(1O2)和超氧自由基阴离子(O2 ),这说明了光催化体系中有效的电子转移(et)和体系间交叉(ISC)过程。
Fig. 1 (a) Schematic diagram for the synthesis of DPP-COF. (b) Measured PXRD pattern of DPP-COF with corresponding simulated patterns. (c) Top view of the 2D crystal structures of DPP-COF. (d) N2 adsorption–desorption isotherm and pore size distribution profile of DPP-COF. (e) FT-IR spectra of monomer DPP-T-CHO, TMT and DPP-COF. (f) Solid state 13C CP/MAS NMR spectra of DPP-COF. (g) Chemical stability measurement of DPP-COF.
Fig. 2(a) HR-TEM image and (b) lattice structure of DPP-COF. (c) FFT pattern of DPP-COF.
Fig. 3(a) Absorption spectra of monomers and DPP-COF with the bandgap calculated from theTauc-plot. (b) Band structure and partial density of states (PDOS) calculated at the DFT/PBE level for DPP-COF. (c) Distribution of holes and electrons of the first singlet excited state for the segment of DPP-COF at the TD-B3LYP/6-31G(d,p) level. The blue and green isosurface represent hole and electron distributions, respectively.
Fig. 4(a) EPR spectra of a mixture of COF (4 mg mL1) and TEMP in EtOH in the dark and upon light irradiation. (b) EPR spectra of a mixture of COF (4 mg mL1) and DMPO in MeCN/DMF (1 : 1) in the dark and upon light irradiation.
https://doi.org/10.1039/D4CC06615D
