Activity boosting of a metal-organic framework by Fe-Doping for electrocatalytic hydrogen evolution and oxygen evolution

Herein, a bimetallic MOF (Co/Fe-MOF) prepared by doping of Fe centers into a Co-MOF structure was explored as a bifunctional electrocatalyst for hydrogen evolution and oxygen evolution. The Fe-doping can greatly enhance the catalytic activity of Co/Fe-MOF, which presents much smaller overpotentials and Tafel slopes than the monometallic Co-MOF in 1.0 ​M KOH solution, and remarkable durability that superior to the corresponding commercial catalysts of Pt/C and RuO2 for both of the two processes. Impressively, the OER activity of Co/Fe-MOF is comparable to the RuO2 and even higher at current densities (≥10 ​mA ​m−2). An electrolyzer by employing the Co/Fe-MOF modified Ni foam as cathode and anode was assembled, which shows better performance and durability for overall water splitting than the system built from Pt/C and RuO2. This work offers thought for future in-depth digging of the potential of MOFs as electrocatalysts and expanding the family of MOFs electrocatalysts.