Tailoring electrochemical efficiency of hydrogen evolution by fine tuning of TiO _x /RuO _x composite cathode architecture

TY - JOUR

T1 - Tailoring electrochemical efficiency of hydrogen evolution by fine tuning of TiO x /RuO x composite cathode architecture

AU - Fedorov, Fedor S.

AU - Vasilkov, Mikhail Y.

AU - Panov, Maxim

AU - Rupasov, Dmitry

AU - Rashkovskiy, Alexander

AU - Ushakov, Nikolay M.

AU - Lee, Jaeho

AU - Hempelmann, Rolf

AU - Kallio, Tanja

AU - Nasibulin, Albert G.

PY - 2019/4/23

Y1 - 2019/4/23

N2 - Here we report an approach to design composite cathode based on TiO x nanotubes decorated with RuO x nanowhiskers for efficient hydrogen evolution. We tailor catalytic activity of the cathodes by adjustment of morphology of TiO x nanotubular support layer along with variation of RuO x loaded mass and assess its performance using electrochemical methods and wavelet analysis. The highest energy efficiency of hydrogen evolution is observed in 1 M H 2 SO 4 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 RuO x 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.

AB - Here we report an approach to design composite cathode based on TiO x nanotubes decorated with RuO x nanowhiskers for efficient hydrogen evolution. We tailor catalytic activity of the cathodes by adjustment of morphology of TiO x nanotubular support layer along with variation of RuO x loaded mass and assess its performance using electrochemical methods and wavelet analysis. The highest energy efficiency of hydrogen evolution is observed in 1 M H 2 SO 4 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 RuO x 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.

KW - Composite cathode

KW - Hydrogen evolution reaction

KW - Ruthenia

KW - Titania nanotubes

KW - Water electrolysis

KW - Wavelet analysis

UR - http://www.scopus.com/inward/record.url?scp=85063411503&partnerID=8YFLogxK

U2 - 10.1016/j.ijhydene.2019.03.019

DO - 10.1016/j.ijhydene.2019.03.019

M3 - Article

VL - 44

SP - 10593

EP - 10603

JO - International Journal of Hydrogen Energy

JF - International Journal of Hydrogen Energy

SN - 0360-3199

IS - 21

ER -