Electroactive Metal–Organic Frameworks Enabling Unidirectional Electrochemical Capacitors and Logic Gates (MOF‐CAPode)

Abstract

ABSTRACT From concept to realization, the integration of porous redox‐active metal–organic frameworks (MOFs) into asymmetric electrochemical capacitors for the assembly of electrochemical capacitor‐diodes (CAPodes) is reported. CAPodes are innovative electrochemical capacitor analogues of diodes, designed for unidirectional charge storage and logic gate applications. The novel devices deliberately utilize two distinct electroactive metal–organic frameworks with characteristic redox potentials acting as positively or negatively polarizable electrode materials, respectively. The first proof‐of‐concept devices presented here make use of the Chichibabin‐like diradicaloid formation upon oxidation of the N,N,N',N' ‐benzidinetetrabenzoate linker in DUT‐65/66 and N,N,N',N' ‐(1,4‐phenylenebis‐(azanetriyl))‐tetrabenzoate in DUT‐232/233 at high oxidation potentials as a positively polarizable electrode material paired with the highly reversible two‐step reduction in Zn(ndi) (ndi 2 − = 1,4‐bis[(3,5‐dimethyl)‐pyrazolate‐4‐yl]naphthalene‐diimide). The novel porous MOF‐CAPode achieves a remarkable figure of merit with rectification ratios (RR) up to RR I = 23 and RR II = 94% at 10 mV s −1 . The new MOF‐based CAPodes operate efficiently in “AND” and “OR” logic gates, demonstrating logic operation under varying input voltages up to 3.0 V and frequencies of up to 40 mHz.