RESUMO
Herein, a nanohybrid material containing graphene-like sheets (GS) and Fe-Co layered double hydroxides nanoflakes (LDHs) was synthesized via simple two-step processes and named Fe-Co LDHs/GS. The Fe-Co LDHs/GS nanohybrid was characterized by various techniques. Fe-Co LDHs nanoflakes were grown on GS in Fe-Co LDHs/GS nanohybrid. The electrochemical surface area of Fe-Co LDHs/GS nanohybrid was obtained 0.05 cm2 based on the Randles-Sevcik equation. The Fe-Co LDHs/GS nanohybrid was applied as an electrocatalyst of HER and OER in a 1.0 M KOH. The electrochemical performance of Fe-Co LDHs/GS nanohybrid was surveyed by several electrochemical methods, and long-term electrochemical stability. The onset potential, overpotential at 10 mA cm-1 current density, and Tafel slope for the Fe-Co LDHs/GS nanohybrid were obtained -0.33 V, -0.43 V (vs. RHE), and 122 mV dec-1, respectively. The Fe-Co LDHs/GS nanohybrid has long-term stability over 35 h in alkaline media toward HER. Furthermore, the onset potential, overpotential at 10 mA/cm, and Tafel slope for the Fe-Co LDHs/GS nanohybrid were obtained as 1.52 V, 1.60 V (vs. RHE), and 44 mV dec-1, respectively. The Fe-Co LDHs/GS nanohybrid has long-term durability over 10 h in alkaline media toward OER.
