Co(OH)2 nanosheet arrays electrodeposited with palladium nanoparticles for hydrogen evolution reaction

Palladium (Pd) nanoparticles in combination with naturally abundant materials are stable and highly active catalysts for hydrogen production . Herein, Co(OH) 2 nanosheet arrays are prepared hydrothermally on graphene/nickel foam (graphene/NF) to produce Co(OH) 2 /graphene/NF which provides the desirable three-dimensional (3D) substrate for subsequent Pd electrodeposition to obtain Pd/Co(OH) 2 /graphene/NF. The materials exhibit excellent durability and catalytic performance in the hydrogen evolution reaction (HER) in an alkaline environment such as a low overpotential of 124  mV at 10 mA cm −2 and Tafel slop of 53 mVdec −1 . The excellent performance is attributed to the synergistic catalytic effects rendered by the nanostructured interfaces between the Pd nanoparticles and Co(OH) 2 nanosheet arrays as well as large surface area . The technique and materials have large potential in energy conversion applications.