Hydrogen Bonds Induced Ultralong Stability of Conductive π-d Conjugated FeCo3(DDA)2 with High OER Activity.

ABSTRACT

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 FeCo3(DDA)2 (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 FeCo3(DDA)2 is responsible for its ultrahigh OER stability. Besides that, FeCo3(DDA)2 also displays a prominent OER activity (an overpotential of 260 mV vs reversible hydrogen electrode (RHE) at a current density of 10 mA cm-2 and a Tafel slope of 46.86 mV dec-1). Density functional theory (DFT) calculations further indicate that the synergistic effect of the Fe and Co sites in FeCo3(DDA)2 contributes to its prominent OER performance. This work provides a new avenue of boosting the electrocatalytic stability of conductive π-d conjugated MOFs.