本文要点：
从NH3和CO2进行尿素的人工光合作用似乎仍然基本上未被探索。本文中，具有双重互穿ffc拓扑的三个同构三维共价有机框架分别被苯、吡嗪和四嗪活性部分功能化。
一系列实验结果揭示了依次为含苯、吡嗪和四嗪骨架的逐渐增强的电导率、集光能力、光生载流子分离效率和对NH3和CO2的共吸附能力。
这反过来赋予了含四嗪的框架对NH3和CO2生产尿素具有优异的光催化活性，产率为523 μmol g−1 h−1，分别比含苯和吡嗪的框架高40和4倍，表明这三种光催化剂的杂环N微环境依赖性催化性能。
这被原位光谱表征和密度泛函理论计算进一步证实。这项工作为尿素的可持续光合作用奠定了基础。
Fig. 1 | Structural schematic and characterization ofCOFs. a Schematic synthesis and (b) FT-IR spectra of 3D-TPT-COF, 3D-PDDP-COF, and 3D-TBBD-COF. c 13C ssNMR spectrum of 3D-TBBD-COF. d N2 sorption isotherms of 3D-TPT-COF (gray), 3D-PDDP-COF (green), and 3D-TBBD-COF (red). PXRD patterns of(e) 3D-TPT-COF,f 3D-PDDP-COF, and (g) 3D-TBBD-COF.
Fig. 2 | Characterization of COFs and urea photoproduction. a Current-voltage (b) UV-vis DRS, c Tauc plots, d Mott−Schottky plots, e energy band structure, f transient photocurrent spectra, and (g) Nyquist plots of 3D-TPT-COF (gray), 3D-PDDP-COF (green), and 3D-TBBD-COF (red). h Urea formation rate using 3DTPT-COF, 3D-PDDP-COF, and 3D-TBBD-COF as photocatalyst. i HR-MS spectra of 3D-TBBD-COF photocatalytic 13CO2 + 14NH3 and 12CO2 + 15NH3 synthesis systems.
Fig. 3 | In situ DRIFT spectra and adsorption structure of COFs. In-situ DRIFT spectra of 3D-TBBD-COF for (a) CO2, b NH3, and (c) CO2 + NH3 adsorption at different times, respectively. Adsorption structures and adsorption energies for CO2, NH3, and CO2 + NH3 on (d) 3D-PDDP-COF and (e) 3D-TBBD-COF (C: gray; N: blue; O: red; H: white). In-situ DRIFT spectra of (f) 3D-TPT-COF, g 3D-PDDP-COF, and (h) 3DTBBD-COF photocoupling CO2 and NH3 for urea production at different times.
Fig. 4 | DFT calculations. a The reaction pathway and (b) corresponding free energy for the generation of urea from CO2 and NH3 on 3D-TBBD-COF.
https://doi.org/10.1038/s41467-025-56307-w
