Hydrogen Bonds Induced Ultralong Stability of Conductive π-d Conjugated FeCo(DDA) with High OER Activity.

Conductive π-d conjugated metal-organic frameworks (MOFs) have attracted wide concerns in electrocatalysis due to their intrinsic high conductivity. However, the poor electrocatalytic stability is still a major problem that hinders the practical application of MOFs. Herein, a novel approach to enhancing the stability of MOF-based electrocatalyst, namely, the introduction of hydrogen bonds (H-bonds), is reported. Impressively, the π-d conjugated MOF FeCo(DDA) (DDA = 1,5-diamino-4,8-dihydroxy-9,10-anthraceneedione) exhibits ultrahigh oxygen evolution reaction (OER) stability (up to 2000 h). The experimental studies demonstrate that the presence of H-bonds in FeCo(DDA) is responsible for its ultrahigh OER stability. Besides that, FeCo(DDA) also displays a prominent OER activity (an overpotential of 260 mV vs reversible hydrogen electrode (RHE) at a current density of 10 mA cm and a Tafel slope of 46.86 mV dec). Density functional theory (DFT) calculations further indicate that the synergistic effect of the Fe and Co sites in FeCo(DDA) contributes to its prominent OER performance. This work provides a new avenue of boosting the electrocatalytic stability of conductive π-d conjugated MOFs.