High‐Temperature Nitridation Induced Carbon Nanotubes@NiFe‐Layered‐Double‐Hydroxide Nanosheets Taking as an Oxygen Evolution Reaction Electrocatalyst for CO2 Electroreduction

Abstract The development of high‐efficiency catalysts for carbon dioxide reduction reaction (CO 2 RR) and oxygen evolution reactions (OER) is an important strategy to solve the current energy crisis. In this paper, solid‐phase exfoliation and electrostatic self‐assembly strategies are developed to couple ultrathin NiFe‐layered‐double‐hydroxide nanosheets and carbon nanotubes (CNT@NiFe‐LDH NS) as an OER catalyst. Then, NiFe nanoparticles anchored on the N‐doped CNT (CNT‐N‐NiFe) for electrocatalyst of CO 2 RR is synthesized via pyrolysis of a mixture of CNT@NiFe‐LDH NS and melamine in a nitrogen atmosphere at 750 °C, utilizing the ultrathin NiFe‐LDH NS as a metal source and CNT as the framework. CNT@NiFe‐LDH NS nanohybrid exhibits a better catalytic activity for OER (with an overpotential of 270 mV at the current density of 20 mA cm –2 and remarkably stable durability) than Bulk NiFe‐LDH in 1 m KOH. Moreover, the CNT‐N‐NiFe catalyst exhibits a Faradaic efficiency of ≈82.6% for the reduction of CO 2 to CO at −0.7 V (vs reversible hydrogen electrode) with a current density of CO 10.2 mA cm –2 . The method of preparing CO 2 RR catalysts provides a new idea of the preparation of bimetallic CO 2 RR electrocatalysts.