Fig. 4. Thermoelectric response evaluation.

a Thermoelectric responses of TpTag-COF/PAN placed between various symmetric KCl aqueous solutions (blue, 0.5 mM; cyan, C; dark yellow, 5 mM; orange, 10 mM; magenta, 50 mM; grey 100 mM). The synchronous time evolution ΔV_oc in response to the solution temperature changes (ΔT, the overlapped curves above the orange arrow) was recorded. b The linear fits of ΔV_oc against ΔT according to Eq. 2; all the fits have R² values higher than 0.99 (blue, 0.5 mM; cyan, C; dark yellow, 5 mM; orange, 10 mM; magenta, 50 mM; grey 100 mM). c The corresponding thermosensation sensitivity and t₊ values were derived from Eq. 2 (average of three different batch experiments, orange, selectivity; cyan, t₊).