Rod-like CoMoO4 grows on lamellar Fe-MOF to assemble the composite electrocatalyst for efficient oxygen evolution reaction

There is an urgent need to design effective and affordable noble metal-free oxygen evolution electrocatalysts for the realization of hydrogen production technology through overall water splitting. In this work, we synthesized CoMoO4/Fe-MOF composite catalysts on nickel foam by solvothermal method and explored them as electrodes towards oxygen evolution reaction. At 10 mA cm−2, CoMoO4/Fe-MOF demonstrated a small overpotential of 238 mV, with a relatively small Tafel slope of 49.22 mV dec-1 and exhibited excellent stability after 30 h of testing. The enhanced OER activity and good durability of CoMoO4/Fe-MOF could be attributed to the self-supported growth of Fe-MOF nanosheets as well as the tight binding to the rod-like CoMoO4. The coupling of CoMoO4 with Fe-MOF established a rich boundary, thus improving conductivity, increasing specific surface area and exposing more active sites. These results suggested that the combination of MOFs with binary transition metal oxides provided an effective route to develop robust and efficient electrocatalysts.