Effect of carbonization temperature on electrocatalytic water splitting of Fe-Co anchored on N-doped porous carbon

Carbonization of Fe-Co based metal organic frameworks (Fe-Co-MOFs) in N2 obtains an electrocatalyst with Fe-Co anchored on N-doped porous carbon. The ratio of Fe and Co in the alloy can be controlled by adjusting the carbonization temperature. The electrocatalytic activity for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) could be enhanced by the subtle Fe-Co modification significantly. Among these electrocatalysts, the Fe-Co/NC-800 presents the best HER and OER activity as well as reaction kinetics. The overpotentials at the current density of 10 ​mA ​cm-2 of Fe-Co/NC-800 are 182 and 279 ​mV (vs. RHE) for HER and OER, respectively. The Tafel slopes of Fe-Co/NC-800 are 157.8 and 42.7 ​mV dec-1 for HER and OER, respectively. The results suggest that adjusting carbonization temperature of Fe-Co-MOFs is an effective method to prepare highly efficient non-noble metal bifunctional electrocatalysts for electrochemical water splitting.