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−2and 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.