A novel, rational, and efficient way to explore high-performance electrocatalysts was developed by controlling the reaction kinetics of the rate-determining step (RDS). Density functional theory (DFT) calculations demonstrate that the RDS for the oxygen evolution reaction driven by transition metal hydroxides/oxides, i.e., surface adsorption of OH−/OOH• species, can be significantly promoted by increasing the electrophilicity of electrocatalysts via hybridization with electron-withdrawing inorganic nanosheets. As predicted by DFT calculation, the hybridization of Ni–Fe-layered double hydroxide (LDH)/Ni–Co-LDH, with RuO2 nanosheets (1.0 wt%) leads to significant lowering of the overpotentials to 207/276 mV at 10 mA cm−2, i.e., one of the smallest overpotentials for LDH-based materials, with the increase in the current density. The necessity of a very small amount of RuO2 nanosheets (1.0 wt%) to optimize the electrocatalyst activity highlights the remarkably high efficiency of the RuO2 addition. The present study underscores the importance of kinetic control of the RDS via hybridization with electron-withdrawing species for exploring novel efficient electrocatalysts.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. NRF- 2017R1A2A1A17069463) and by the Korea government (MSIT) (No. NRF-2017R1A5A1015365). The experiments at PAL were supported in part by MOST and POSTECH.
© 2018, The Author(s).