Tailoring electrochemical efficiency of hydrogen evolution by fine tuning of TiOx/RuOx composite cathode architecture. (23rd April 2019)

• Record Type: Journal Article
• Authors: Fedorov, Fedor S.; Vasilkov, Mikhail Y.; Panov, Maxim; Rupasov, Dmitry; Rashkovskiy, Alexander; Ushakov, Nikolay M.; Lee, Jaeho; Hempelmann, Rolf; Kallio, Tanja; Nasibulin, Albert G.
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 21(2019)
• Page Start: 10593
• Page End: 10603
• Publication Date: 2019-04-23
• Subjects: Titania nanotubes -- Ruthenia -- Composite cathode -- Water electrolysis -- Hydrogen evolution reaction -- Wavelet analysis; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.03.019
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Here we report an approach to design composite cathode based on TiOx nanotubes decorated with RuOx nanowhiskers for efficient hydrogen evolution. We tailor catalytic activity of the cathodes by adjustment of morphology of TiOx nanotubular support layer along with variation of RuOx loaded mass and assess its performance using electrochemical methods and wavelet analysis. The highest energy efficiency of hydrogen evolution is observed in 1 M H2 SO4 electrolyte to be ca. 64% at −10 mA/cm 2 for cathodes of the most developed area, i.e. smaller diameter of tubes, with enhanced RuOx loading. The efficiency is favored by detachment of small hydrogen bubbles what is revealed by wavelet analysis and is expressed in pure noise at wavelet spectrum. At increased current density, −50 or −100 mA/cm 2, better efficiency of composite cathodes is supported by titania nanotubes of larger diameter due to an easier release of large hydrogen bubbles manifested in less periodic events appeared in the frequency region of 5–12 s at the spectra. We have shown that efficiency of the catalysts is determined by a pre-dominant type of hydrogen bubble release at different operation regimes depending on specific surface and a loaded mass of ruthenia. Graphical abstract: Image 1 Highlights: We have fabricated cathode based on TiOx nanotubes decorated by RuOx nanowhiskers. Surface morphology of cathode is tailored to facilitate gas bubble detachment. A pre-dominant type of hydrogen bubble release is resolved using wavelet analysis. The best HER efficiency is up to 64% associated with small bubble detachment.