▎ 摘　　要

As functional molecules, amino acids have attracted great attention in the field of material sciences due to their interactive sites. New studies have shown the electrocatalytic activity capability of amino-acid-functionalized graphene oxide (GO) toward the oxygen evolution reaction (OER). The improved active sites and further tunable and huge surface area after L-lysine functionalization on reduced graphene oxide (Ly-rGO) offer significant opportunities for further enhancement in the OER activity. Herein, the functionalization of GO with terminal nitrogen-containing groups (L-lysine) results in efficient and stable electrocatalytic activity for OER with a lower overpotential of 0.33 V at 10 mA cm(-2) and a lower Tafel slope of 80 mV dec(-1). Electrochemical impedance spectroscopic of Ly-rGO also shows a lower R-ct = 29.58 Omega and an excellent current stability for 5000 s at an onset potential of 1.29 V vs SCE in 0.5 M KOH. Morphological studies based on high-resolution transmission electron microscopy confirm that the size of Ly-rGO is similar to 5 nm. X-ray photoelectron spectroscopic analysis confirms the surface functionalization of GO by lysine (Ly-rGO) from the binding energies of C-N, C-O, and C-C. From this perspective, our findings emphasize the usefulness of metal-free amino-acid-functionalized carbon-based electrocatalysts for OER, which is an important water-splitting reaction, and demonstrates that they may be keys toward enhancement in activities.