Synergistic effect of charge transfer and short H-bonding on nanocatalyst surface for efficient oxygen evolution reaction

Abstract

Exploring advanced electrocatalysts with unprecedented catalytic efficiency for oxygen evolution reaction (OER) of water splitting is of great importance in many energy conversion and storage systems. Based on our previous findings that short H-bonding on reconstructed βII-Li2CoSiO4 (LCS) nanocrystal surface to enhance OER activity by facilitating proton transfer/dissociation and an electronic push/pull effect of Co and Fe doping on OER performance of Ni-based hydroxides, here we report both combination of Fe-Co synergistic effect with charge transfer and short H-bonding on Li2CoxFe1-xSiO4 (LCxF1-xS, 0 < x < 1) nanocatalyst surface can further enhance OER performances of water splitting. Especially, LiC0.5F0.5S exhibits superior OER activity and super-long term stability (no fade after 10,000 CV cycles, high temperature of 80 ℃, and 100 h OER measurement at a low overpotential of 0.3 V with high current density of 80 mA cm−2). Insight of the ultrahigh OER performance of LC0.5F0.5S is suggested to attribute to the short H-bonding formed on the constructed surface and the synergistic coupling effect between Fe and Co with charge transfer, which leads to favorable electronic structure of TM active sites, promotes proton out of the oxygen on Co site and generates H2O on Fe site by proton transfer.