Constructing accelerated charge transfer channels along V-Co-Fe via introduction of V into CoFe-layered double hydroxides for overall water splitting

A series of self-supported electrocatalysts composed of tri-metallic CoFeV-LDHs generated on conductive carbon cloth (denoted as CoFeV@CC) have been constructed. The specific interaction among Co, Fe and V is systematically revealed via tuning the molar ratios of M 2+ :M 3+ and Fe 3+ :V 3+ in these tri-metallic LDHs. Finally, the optimal synergistic effect is reached when the molar ratios of M 2+ :M 3+ and Fe 3+ :V 3+ are respectively 4:1 and 1:1, resulting in the product named Co 8 FeV@CC, which displays the best overall OER and HER performance. Only rather low overpotentials of 235 and 182 mV are required to attain the current density of 100 mA cm −2 with a Faradaic efficiency of nearly 100 % for OER and HER, respectively. Co 8 FeV@CC can thus be applied as both an anode and cathode in the symmetrical two-electrode and possesses a current density of 100 mA cm −2 at the cell voltage of 1.65 V, and further demonstrates ultra-high stability for 100 h.