Formation of Hierarchical Structure Composed of (Co/Ni)Mn-LDH Nanosheets on MWCNT Backbones for Efficient Electrocatalytic Water Oxidation

Active, stable, and cost-effective electrocatalysts are attractive alternatives to the noble metal oxides that have been used in water splitting. The direct nucleation and growth of electrochemically active LDH materials on chemically modified MWCNTs exhibit considerable electrocatalytic activity toward oxygen evolution from water oxidation. CoMn-based and NiMn-based hybrids were synthesized using a facile chemical bath deposition method and the as-synthesized materials exhibited three-dimensional hierarchical configurations with tunable Co/Mn and Ni/Mn ratio. Benefiting from enhanced electrical conductivity with MWCNT backbones and LDH lamellar structure, the Co5Mn-LDH/MWCNT and Ni5Mn-LDH/MWCNT could generated a current density of 10 mA cm–2 at overpotentials of ∼300 and ∼350 mV, respectively, in 1 M KOH. In addition, the materials also exhibited outstanding long-term electrocatalytic stability.