報文
Effects of Oxide Composition on Structure, Surface Morphology, and Oxygen Evolution Behaviors of IrO2-Ta2O5/Ti Anodes Prepared at a High Temperature
2015 年 83 巻 4 号 p. 256-261
詳細
2015 年 83 巻 4 号 p. 256-261
Catalytic coatings comprising a mixture of IrO2 and Ta2O5 were prepared at 50–80 mol% Ir by thermal decomposition at 470°C, and the crystallographic structures and surface morphologies were investigated. XRD analysis and high-resolution SEM observation using low accelerated incident beam revealed that decreasing Ir ratio made a phase transition of IrO2 from crystalline to partly amorphous, and nano IrO2 particles of 10 nm or less and nano chains made of them, which were uniformly dispersed on the flat area of the coating, were generated at 50–60 mol% Ir. The relationship between nano-scale surface morphology of the coating and electrocatalysis for oxygen evolution in H2SO4 solutions was also investigated. The active surface area and oxygen evolution current increased with reducing Ir ratio. The electrocatalysis of the IrO2-Ta2O5 coatings for oxygen evolution is possible to be attributed to nano IrO2 particles.
