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

The accelerated charge transfer channels are constructed via the introduction of vanadium into CoFe-LDHs. The overall OER and HER performance are enhanced due to the interactions among three metal components. Herein, vanadium is responsible for optimizing the electronic structure while cobalt and iron play key roles in regulating the HER and OER performance, respectively. [Display omitted] • Composition, microstructure and morphology act as the catalyst design principles. • The charge transfer channels are constructed by introducing V into CoFe-LDHs. • The synergistic effect among metal components in CoFeV-LDHs is clearly revealed. • The dynamics barrier of OER is reduced via adjusting the molar ratio of metal ions. • The excellent HER performance of LDHs is performed through activating metal sites. 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 M2+:M3+ and Fe3+:V3+ in these tri-metallic LDHs. Finally, the optimal synergistic effect is reached when the molar ratios of M2+:M3+ and Fe3+:V3+ 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. [ABSTRACT FROM AUTHOR]