Highly active bifunctional electrocatalyst: Nanoporous (Ni,Co) 0. 85 Se anchored on rGO for water and hydrazine oxidation

Abstract

It is an effective strategy to decrease water splitting overpotential by designing high-performance oxygen evolution reaction (OER) electrocatalyst or substituting OER by hydrazine electrooxidation (HzOR). Herein, we fabricated bifunctional (Ni,Co)0.85Se/rGO with nanoporous structure via electrodeposition towards HzOR and OER. In comparison with (Ni,Co)0.85Se and NF, superior electrocatalytic activity and stability towards HzOR and OER were observed for (Ni,Co)0.85Se/rGO. The synergistic effects of (Ni,Co)0.85Se with rGO, high electrochemical surface area (ECSA), high electrical conductivity and the rapid release rate of bubbles from electrode surface induced by its superaerophobic result in superior performance of (Ni,Co)0.85Se/rGO. The OER process requires a low overpotential of 247 mV at 10 mA cm−2, and a high durability of 86.1% during 48 h long-term test at 10 mA cm−2. When changing OER with HzOR, HzOR process can generate a high current density of 211 mA cm−2 at a potential of 0.2 V vs RHE, and a high stability of 92.3% after 24 h test at a high current density of 50 mA cm−2. This study displays a versatile, cost-effective and industrial strategy to produce highly active catalysts for bifunctional application.