Synergistically modulating the active-site density and charge-transfer in covalent organic frameworks for boosting electrocatalytic water splitting

Two bicarbazole 2D COFs, NUST-69/70, with distinct electronics, show efficient water-splitting and good bifunctional HER/OER activity. Notably, NUST-70 with D-A benzothiadiazole moiety, modulates sites/charge transfer, boosting OER at 292 mV.