过电位
双功能
析氧
电催化剂
催化作用
氧气
化学
密度泛函理论
纳米棒
化学工程
材料科学
无机化学
纳米技术
电化学
物理化学
电极
计算化学
有机化学
工程类
生物化学
作者
Jianan Xie,Yilong Chen,Zhanglong He,Shan Liu,Yuling Liu,Bin Li,Tianjian Xu,Xiaohui Ning,Shuguang Chen,Taotao Zeng,Hao He
出处
期刊:ACS applied nano materials
[American Chemical Society]
日期:2024-07-30
卷期号:7 (15): 18027-18035
被引量:1
标识
DOI:10.1021/acsanm.4c03521
摘要
Developing efficient MnO2-based bifunctional catalysts is a considerable challenge due to slow oxygen reduction reaction (ORR) kinetics and the limited activity of the oxygen evolution reaction (OER). Herein, an efficient bifunctional catalyst Ni/α-MnO2 is prepared by a straightforward solid-phase synthesis method, enabling the anchoring of Ni atoms onto the α-MnO2 surface. The electrochemically active surface area is significantly enhanced due to the generation of oxygen vacancies and presence of atomic Ni sites. After Ni decoration, the half-wave potential of the ORR is elevated to 0.82 V, while the overpotential for the OER is reduced to 366 mV, resulting in an exceptionally low overall oxygen overpotential (ΔE = 0.79 V). Density functional theory calculations reveal that the d-band center of Mn exhibits negative shifts, consequently lowering the energy barrier for the conversion of OOH* to O* in the ORR and that of OH* to O* in the OER. In a secondary zinc–air battery, a supreme power density of 290 mW cm–2 is acquired at a current density of 350 mA cm–2, surpassing the performance of pristine α-MnO2. This work offers valuable guidance for the development of high-performance MnO2-based bifunctional catalysts.
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