Deposition of Tungsten Metal by an Immersion Process. Issue 6 (1st January 2017)

• Record Type: Journal Article
• Authors: Small, Leo J.; Brumbach, Michael T.; Clem, Paul G.; Spoerke, Erik D.
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 6(2017)
• Page Start: D269
• Page End: D274
• Publication Date: 2017-01-01
• Subjects: coating -- electrodeposition -- electroless deposition -- immersion -- tungsten; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0131706jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : A new multi-step, solution-phase method for the spontaneous deposition of tungsten from a room temperature ethereal solution is reported. This immersion process relies on the deposition of a sacrificial zinc coating which is galvanically displaced by the ether-mediated reduction of oxophilic WCl6 . Subsequent thermal treatment renders a crystalline, metallic tungsten film. The chemical evolution of the surface and formation of a complex intermediate tungsten species is characterized by X-ray diffraction, infrared spectroscopy, and X-ray photoelectron spectroscopy. Efficient metallic tungsten deposition is first characterized on a graphite substrate and then demonstrated on a functional carbon foam electrode. The resulting electrochemical performance of the modified electrode is interrogated with the canonical aqueous ferricyanide system. A tungsten-coated carbon foam electrode showed that both electrode resistance and overall electrochemical cell resistance were reduced by 50%, resulting in a concomitant decrease in redox peak separation from 1.902 V to 0.783 V. This process promises voltage efficiency gains in electrodes for energy storage technologies and demonstrates the viability of a new route to tungsten coating for technologies and industries where high conductivity and chemical stability are paramount.