Synthesis and Oxygen Electrocatalysis of Iridium Oxide Nanosheets
Synthesis and Oxygen Electrocatalysis of Iridium Oxide Nanosheets
复制标题
DOI：
10.1007/s12678-016-0348-4
复制
发表时间：
2017-03
期刊：
影响因子：
3.1
通讯作者：
Daisuke Takimoto;K. Fukuda;Shu Miyasaka;T. Ishida;Y. Ayato;D. Mochizuki;W. Shimizu;W. Sugimoto
中科院分区：
文献类型：
--
作者：
Daisuke Takimoto;K. Fukuda;Shu Miyasaka;T. Ishida;Y. Ayato;D. Mochizuki;W. Shimizu;W. Sugimoto
金红石型二氧化铱（IrO 2）是一种众所周知的电催化剂，其纳米颗粒形式最近作为电解槽和燃料电池中的催化剂和助催化剂引起了人们的关注。在本研究中，我们成功地通过剥离层状铱酸HxIryOz·nH 2 O，它是通过层状铱酸钾，KxIryOz·nH 2 O的质子交换制备的单晶二氧化铱（IrO 2）纳米片的厚度小于0.7 nm的。IrO 2纳米片电极的电化学活性表面积与3-nm IrO 2纳米颗粒的电化学活性表面积相似或略低。尽管活性表面积较低，但IrO 2纳米片在0.1 M HClO 4中的析氧反应的质量活性比IrO 2纳米颗粒高6倍，电压为1.55 V，与可逆氢电极相比（17.4 vs. 2.9 A g-1）。当IrO 2纳米片被添加到商业Pt/C作为助催化剂，增加对高电位循环的稳定性。在1.0 - 1.5 V的电位循环后，复合催化剂的氧还原活性是未改性Pt/C的2倍。这种耐久性的提高归因于IrO 2纳米片的改性抑制了颗粒在电位循环测试中的生长。图形摘要IrO 2纳米片作为析氧和还原O2的电催化剂具有高活性
Rutile-type iridium dioxide (IrO2) is a well-known electrocatalyst, and its nanoparticle form has recently attracted attention as catalysts and co-catalysts in electrolyzers and fuel cells. In this study, we have successfully synthesized single crystalline iridium dioxide (IrO2) nanosheets with thickness of less than 0.7 nm via exfoliation of layered iridic acid HxIryOz·nH2O, which was prepared via proton exchange of layered potassium iridate, KxIryOz·nH2O. The electrochemically active surface area of the IrO2nanosheet electrode was similar to or slightly lower than that of 3-nm IrO2nanoparticles. Despite the lower active surface area, the mass activity for oxygen evolution reaction of IrO2nanosheets was six times higher compared to that of IrO2nanoparticles in 0.1 M HClO4at 1.55 V vs. the reversible hydrogen electrode (17.4 vs. 2.9 A g−1). When IrO2nanosheets were added to commercial Pt/C as a co-catalyst, increased stability against high potential cycling was obtained. After potential cycling between 1.0 and 1.5 V, the composite catalyst exhibited two times higher oxygen reduction activity compared to non-modified Pt/C. This durability enhancement is attributed to the suppression of the particle growth during the potential cycling test by the modification with IrO2nanosheets.Graphical AbstractIrO2nanosheets are highly active as electrocatalysts for O2evolution and O2reduction