文献类型：期刊文献

英文题名：Hollandite Structure Kx≈025IrO2 Catalyst with Highly Efficient Oxygen Evolution Reaction

作者：Sun, Wei[1];Song, Ya[2,3];Gong, Xue-Qing[2,3];Cao, Li-mei[1];Yang, Ji[1]

机构：[1]E China Univ Sci & Technol, Sch Resources & Environm Engn, State Environm Protect Key Lab Environm Risk Asse, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Key Lab Adv Mat, Ctr Computat Chem, 130 Meilong Rd, Shanghai 200237, Peoples R China;[3]E China Univ Sci & Technol, Res Inst Ind Catalysis, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2016

卷号：8

期号：1

起止页码：820

外文期刊名：ACS APPLIED MATERIALS & INTERFACES

收录：;EI(收录号：20160401832784);WOS:【SCI-EXPANDED(收录号:WOS:000368563000097)】；

基金：This research is based on work supported by the National Natural Science Foundation of China (Grants 21177037, 21277045, and 21322307). We thank beamline BL14W1 (Shanghai Synchrotron Radiation Facility) for providing the beam time.

语种：英文

外文关键词：OER; hydrothermal; hollandite iridate; electronic structure; DFT

摘要：Oxygen evolution reaction (OER) catalysts with high activity are of particular importance for renewable energy production and storage. Here, we prepare Kx approximate to 0.25IrO2 catalyst that exhibits an excellent OER activity compared to IrO2, which is univerally acknoweledged as a state-of-the-art OER catalyst. The prepared catalyst reflects a small overpotential 0.35 V at a current density of 10 mA cm(-2) and a lower Tafel slope (65 mV dec(-1)) compared to that for IrO2 (74 mV dec(-1)). The performed X-ray photoelectron spectroscopy (XPS) and X-ray adsorption (XAS) experiments indicate that the Ir-site of Kx approximate to 0.25IrO2 has a lower valence and more Ir-5d occupied states, suggesting more electrons on the Ir site. The extra electrons located on the Ir site and distorted IrO6 octahedral symmetry have a significant effect on the 5d orbital energy distribution which is verified by our DOS calculation. The performed DFT calculations state that the Kx approximate to 0.25IrO2 essentially obtains good OER performance because it has a lower theoretical overpotential (0.50 V) compared to IrO2 (0.61 V).