The removal rate of TABN-COF in (a) pH range 5–9 (25 °C, C₀ = 6 mM, m = 10 mg, V = 5 mL); (b) different competitive ions and simulated seawater (25 °C, C₀ = 0.6 mM, C_competive = 6 mM, m = 10 mg, V = 5 mL); (c) recycle tests (25 °C, C₀ = 6 mM, m = 10 mg, V = 5 mL) and (d) removal rate of I₃⁻ by TABN-COF after treatment with acids, base, oxidant and reductant (25 °C, C₀ = 6 mM, m = 10 mg, V = 5 mL).