Preparation of Au nanosheets supported on Ni foam and its electrocatalytic performance towards NaBH4 oxidation

Abstract

The unique Au nanosheets (Au NSs) are electrodeposited uniformly on Ni foam substrate via a one-step potentiostatic electrodeposition technique. The electrode is characterized by scanning electron microscopy equipped with energy dispersive X-ray spectrometer and X-ray diffractometer. It shows a unique open structure allowing the full utilization of Au surface active sites. NaBH4 electrooxidation in KOH solution on the Au NSs/Ni foam electrode are studied by linear sweep voltammetry and chronoamperometry. The electrode exhibits a high catalytic performance outperforming the Au particles made by the same method. At the oxidation potential of 0V, the current density of 827mAcm−2 can be achieved on Au NSs/Ni foam electrode, and only 219mAcm−2 was obtained on Au NPs/Ni foam electrode, indicating that the catalytic activity is increased by 278%, which is attributed to the porous 3D structure, ensuring the full utilization of Au surfaces. Besides, H2 generated by NaBH4 hydrolysis can quickly diffuse away from the electrode, preventing surface active sites of Au from blocking by adsorbed gas bubbles.