A hierarchical electrode is prepared with Au nanowires grown on nickel foam. With large specific active surface area, it is used for producing syngas (H-2/O-3) with controllable ratio, through electrochemical process in DMF. The synthetic innovation lies in the use of 3-cyanopropyltriethoxysilane, to achieve the adsorption of appropriate amount of Au seeds for the one-dimensional growth of ultrathin Au nanowires (d approximate to 5 nm). With the nanowires forest on the three-dimensional porous nickel foam substrate, syngas is produced by electro-catalysis with high overall Faradic efficiency and tunable H-2/CO ratios. This synthetic strategy opens a facile way to synthesize the hierarchical nanostructured materials, and broaden the choice of the catalysts for electrochemical applications. (C) 2020 Elsevier Inc. All rights reserved.