Sub-2 nm IrO_(2)/Ir nanoclusters with compressive strain and metal vacancies boost water oxidation in acid  

作　　者：Zhijuan Liu Guangjin Wang Jinyu Guo Shuangyin Wang Shuang-Quan Zang 

机构地区：[1]Henan Key Laboratory of Crystalline Molecular Functional Materials,Henan International Joint Laboratory of Tumor Theranostical Cluster Materials,Green Catalysis Center,and College of Chemistry,Zhengzhou University,Zhengzhou 450001,China [2]Hunan University,State Key Laboratory of Chem/Bio-sensing and Chemometrics,College of Chemistry and Chemical Engineering,Changsha 410082,China [3]School of Materials Science and Energy Engineering,Foshan University,Foshan 528000,China

出　　处：《Nano Research》2023年第1期334-342,共9页纳米研究（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Nos.92061201,21825106,and 22102155);the China Postdoctoral Science Foundation(Nos.2021M692909 and 2022T150587);the Program for Innovative Research Team(in Science and Technology)in Universities of Henan Province and Zhengzhou University(No.19IRSTHN022);the Key Scientific and Technological Project of Henan Province(No.2021102210027).

摘　　要：IrO_(2)exhibits good stability but limited electrocatalytic activity for oxygen evolution reaction in acid.Defect engineering is an effective strategy to improve the intrinsic ability of electrocatalysts by tailoring their electronic structure.Herein,we have successfully synthesized IrO_(2)/Ir heterophase with compressive strain and metal vacancies via a simple substitution-etching method.In virtue of the solubility of Cr in strong alkali,metal vacancies could be formed at surface after etching Cr-doped IrO_(2)/Ir in alkali,which leaded to modulated electronic structure.Meanwhile,the substitution of Cr with smaller atom radius would induce the formation of compressive strain and the relocated atoms made the d-band center shifted.With the regulated electronic structure and tuned d-band center,the obtained electrocatalyst only needed 285 mV to reach 10 mA·cm^(−2)in 0.1 M HClO4.Reaction kinetic has been rapidly accelerated as indicated by the smaller Tafel slope and charge transfer resistance.Theoretical calculations revealed that the d-band center and charge density distribution have been regulated with the introduction of defects in IrO_(2)/Ir,which significantly decreased the free energy barrier of rate determining step.This work provides a valuable reference to design effective and defects-rich electrocatalysts.

关 键 词：IrO_(2)/Ir nanoclusters compressive strain metal vacancies d-band center water oxidation in acid 

分 类 号：O64[理学—物理化学]