A novel IrO2 electrode with iridium–titanium oxide interlayers from a mixture of TiN nanoparticle and H2IrCl6 solution

Abstract

A novel IrO 2 anode on titanium substrate with iridium-titanium oxide interlayer (Ti/IrO x -TiO 2 /IrO 2 ) was prepared and investigated for oxygen evolution. IrO x -TiO 2 interlayer was coated on titanium substrate by impregnation-thermal decomposition method from a mixture of TiN nanoparticles and H 2 IrCl 6 solution at 500°C. The results showed that the service life of Ti/IrO x -TiO 2 /IrO 2 was a factor of six times longer than that of Ti/IrO 2 , which was attributed to the IrO x -TiO 2 interlayer, it could form a metastable solid solution between IrO x and thin titanium oxide layer on titanium substrate during calcination. The interlayer contributed to the decrease in migration rate of oxygen atom or molecule toward substrate and the increase in bonding force among IrO 2 layer, interlayer, and substrate. Therefore, besides keeping high electrocatalytic activity, the service life of Ti/IrO x -TiO 2 /IrO 2 electrode was greatly improved, and its overall electrocatalytic performance for oxygen evolution was increased as well.

The Stability Challenges of Oxygen Evolving Catalysts: Towards a Common Fundamental Understanding and Mitigation of Catalyst Degradation

“…The extent of the delamination of the baseline Ti/IrO 2 electrode was more severe than that of the Ti/IrO x ‐TiO 2 /IrO 2 , with the latter lasting 420 h more at 3 A cm −2 in a 4 m H 2 SO 4 solution at 30 °C. SEM confirmed that delamination was not as pronounced for the interlayer electrode, as shown by the relative sizes of the delaminated and catalyst‐free spots supposedly lost during the ALT process (up to 50 μm × 50 μm versus 500 μm × 600 μm for the interlayer sample and reference case, respectively) …”

Stabilitätsanforderungen von Elektrokatalysatoren für die Sauerstoffentwicklung: der Weg zu einem grundlegenden Verständnis und zur Minimierung der Katalysatordegradation

“…Die Ti/IrO 2 ‐Vergleichselektrode zeigte stärkere Delaminierung als das Ti/IrO x ‐TiO 2 /IrO 2 , und dieses hielt in einer 4 m H 2 SO 4 ‐Lösung bei 30 °C und 3 A cm −2 auch 420 h länger. Die SEM bestätigte eine weniger ausgeprägte Delaminierung bei der Zwischenschichtelektrode, erkennbar an der relativen Größe delaminierter sowie katalysatorfreier Stellen, die vermutlich während des ALT‐Prozesses entstanden sind (bis zu 50 μm × 50 μm für die Zwischenschichtprobe gegenüber 500 μm × 600 μm in der Referenzprobe) …”

Super-Nernstian Potentiometric pH Sensor based on the Electrodeposition of Iridium Oxide Nanoparticles

“…In general, iridium oxide has been widely preferred as a coating material for pH sensors due to its stability against dissolution, potential, chemical stability over a wide range of temperatures (up to 250 o C), fast response, low sensitivity towards ions or redox interferences, and wide pH response range (Marzouk et al, 1998;Xu et al, 2010). Because of these benefits, iridium oxide coated metal-based pH electrodes have been investigated for various applications, such as Severinghaus-type CO2 sensors for oil and gas applications; micro-environmental studies; microsystems for cell culture; and biomedical applications Ges et al, 2007;Johnson et al, 2007).…”