Block copolymer-templated electrodeposition of mesoporous Au-Ni alloy films with tunable composition

Abstract

The fabrication of mesoporous bimetallic alloys has attracted significant attention in recent years due to their higher catalytic activity and stability compared to monometallic mesoporous metals. In this work, we have utilized the soft-templated electrochemical deposition procedure by electrochemically reducing Au and Ni precursors in the presence of block copolymer micelles to form mesoporous bimetallic Au-Ni films at the appropriate applied potential. The as-prepared mesoporous Au-Ni films exhibit uniform mesopores throughout the entirety of the films without any visible cracks and good distribution of the composing elements. The Au and Ni contents in the mesoporous Au-Ni films can be conveniently controlled by adjusting the compositions of the Au and Ni precursors in the initial precursor solution, respectively. When employed as electrocatalysts for MOR, the mesoporous bimetallic Au-Ni films exhibit significantly enhanced electrocatalytic activity compared to the pure mesoporous Au film due to the synergistic effects arising from the multimetallic component and improved accessibility to the active sites as a result of the mesostructure. These findings highlight the promising potential of the as-prepared mesoporous bimetallic Au-Ni films for practical applications in direct methanol fuel cells (DMFCs).