Hierarchical wheat-like Au–Pd heterostructures with enhanced catalytic activity toward methanol electrooxidation

In this report, a simple, facile, controllable, and green one-step electrochemical co-deposition method was developed for the preparation of hierarchical wheat-like Au–Pd heterostructures on a glassy carbon electrode (GCE) without any template or surfactant, only using l -glutamic acid as a growth directing agent. The control experiments associated with the applied potential, the molar ratio of HAuCl 4 to PdCl 2 , electrodeposition time, and concentration of l -glutamic acid were investigated in details. Meanwhile, the electrochemical experiments demonstrate the superior electrocatalytic activity of the Au–Pd heterostructures toward methanol oxidation, achieving a maximum catalytic current density of 45.8   mA   cm −2 in the presence of 0.5   M methanol, much larger than those on pure Au (5.4   mA   cm −2 ) or Pd (25.0   mA   cm −2 ) under the same conditions.