Fig. 3: Optical and electronic property studies.

a UV-vis DRS spectra of IQO-COF-1, Am-COF-1 and Im-COF-1 (inset shows the corresponding Tauc plots). b Mott-Schottky plots of IQO-COF-1. c Energy band structure diagram. d Transient photocurrents under visible light irradiation. e EIS Nyquist plots. f Lifetime analysis by TCSPC of IQO-COF-1, Am-COF-1 and Im-COF-1. g 2D transient absorption surface plots of IQO-COF-1. h fs-TA spectra of IQO-COF-1. i Normalized decay kinetics probed at the maximum transient absorption signal of different COFs. NHE, normal hydrogen electrode.