Graphene-Interfaced NiCu-Layered Double Hydroxide Electrocatalyst for Hydrogen Production via Water Splitting
Manjupriya Jothi, Paulraj Gnanasekar, Gowthambabu Vellingiri, Suwathaa Venkataprabha, Tien Khee Ng, Boon S. Ooi, K. Jeganathan
Abstract
The widespread use of robust catalysts for water-splitting remains limited in practical use due to the instability of conductive supports in harsh electrolytes. This instability leads to the loss of electrocatalytic activity, eventually rendering the electrocatalyst ineffective. Therefore, there is an urgent need to develop more robust and stable electrocatalysts that can withstand harsh conditions and ensure long-term durability and sustainability. We address this challenge by introducing a highly stable hybrid electrode that combines graphene-coated nickel foam with nickel and copper-layered double hydroxide (NiCu-LDH) for water splitting. This unique hybrid electrode has enabled us to achieve 420 h of overall water-splitting performance at the applied potential of 2 V. To optimize the catalyst for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), we systematically investigated different Ni/Cu ratios in the NiCu-LDH. The exceptional stability of these NiCu-LDH hybrid electrodes, particularly the interfacial graphene layer, makes them highly promising for long-lasting and effective water-splitting applications. The synergistic interaction between the NiCu-LDH and graphene layers, and its unique two-dimensional structure with robust carbon–carbon bonds confer exceptional structural integrity, empowering the electrode to withstand deformation and maintain its catalytic performance over extended periods.