Fig. 2. Structural characterization and H₂O₂ evolution performance of Btt-based COFs.

a PXRD patterns of TpaBtt, TapbBtt, and TaptBtt. b TEM images of TpaBtt, TapbBtt and TaptBtt. c Photocatalytic activity of TpaBtt, TapbBtt and TaptBtt for H₂O₂ generation in pure water without any sacrificial agents. Conditions: water (10 mL), catalyst (15 mg), 300 W Xe lamp, λ > 420 nm. d Effects of TaptBtt dosage on H₂O₂ synthesis in water. e PXRD patterns of various degrees of crystallinity in TaptBtt. f Effects of TaptBtt crystallinity on H₂O₂ synthesis in water. Conditions: water (50 mL), catalyst (15 mg), 300 W Xe lamp, λ > 420 nm. g Apparent quantum efficiency of TaptBtt. Conditions: water (60 mL), catalyst (75 mg), 300 W Xe lamp, λ = 400, 420, 450, 475, and 520 nm. h Solar-to-chemical conversion efficiency of TaptBtt (conditions: water (60 mL), catalyst (75 mg)) under simulated AM 1.5 G sunlight irradiation and efficiency comparison of this work with other reported photocatalysts.