TY - JOUR
T1 - Engineering NiFe layered double hydroxide by valence control and intermediate stabilization toward the oxygen evolution reaction
AU - Xu, Zhenxing
AU - Ying, Yiran
AU - Zhang, Guoge
AU - Li, Kongzhe
AU - Liu, Yan
AU - Fu, Nianqing
AU - Guo, Xuyun
AU - Yu, Fei
AU - Huang, Haitao
N1 - Funding Information:
This work is supported by the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. PolyU152140/19E), the National Natural Science Foundation of China (Grants No. 61604058 and 22002192), the Natural Science Foundation of Guangdong Province and the Guangzhou Science and Technology Department (201904010212 and 202002030058). S/TEM work was carried out at the Hong Kong Polytechnic University.
Publisher Copyright:
© 2020 The Royal Society of Chemistry.
PY - 2020/12/28
Y1 - 2020/12/28
N2 - NiFe layered double hydroxide (LDH) is one of the most promising candidates for oxygen evolution reaction (OER) electrocatalysts. However, it is still challenging to design NiFe LDH with both high activity and good stability. Herein, NiFe LDH-Ni(iii)Li is synthesized by a facile approach through valence control of Ni ions and selective doping of Li. Ni(iii) ion percentage is significantly increased from less than 60% to 72.5% in the LDH thanks to the combined benefits of electrochemical oxidation, Mo-leaching and Li-doping. The catalytic activity of NiFe LDH-Ni(iii)Li is greatly promoted because the eg electron occupancy of Ni3+ approaches one, producing optimal bond strength with O. Moreover, density functional theory calculations reveal that Li-doping reduces the adsorption energy difference between ∗OOH and ∗OH from 3.16 eV to 2.79 eV by the stabilization of ∗OOH, decreasing the energy barrier of the rate-determining step by 0.29 eV. At the same time, higher covalency of Ni-O bonds results from the enlarged overlap between Ni 3d and O 2p orbitals, further enhancing the OER kinetics. Consequently, NiFe LDH-Ni(iii)Li exhibits excellent OER performance (overpotential of 248 mV at 10 mA cm-2 on a flat current collector). This work provides a promising technique for engineering the electronic structure of LDH toward outstanding OER properties. This journal is
AB - NiFe layered double hydroxide (LDH) is one of the most promising candidates for oxygen evolution reaction (OER) electrocatalysts. However, it is still challenging to design NiFe LDH with both high activity and good stability. Herein, NiFe LDH-Ni(iii)Li is synthesized by a facile approach through valence control of Ni ions and selective doping of Li. Ni(iii) ion percentage is significantly increased from less than 60% to 72.5% in the LDH thanks to the combined benefits of electrochemical oxidation, Mo-leaching and Li-doping. The catalytic activity of NiFe LDH-Ni(iii)Li is greatly promoted because the eg electron occupancy of Ni3+ approaches one, producing optimal bond strength with O. Moreover, density functional theory calculations reveal that Li-doping reduces the adsorption energy difference between ∗OOH and ∗OH from 3.16 eV to 2.79 eV by the stabilization of ∗OOH, decreasing the energy barrier of the rate-determining step by 0.29 eV. At the same time, higher covalency of Ni-O bonds results from the enlarged overlap between Ni 3d and O 2p orbitals, further enhancing the OER kinetics. Consequently, NiFe LDH-Ni(iii)Li exhibits excellent OER performance (overpotential of 248 mV at 10 mA cm-2 on a flat current collector). This work provides a promising technique for engineering the electronic structure of LDH toward outstanding OER properties. This journal is
UR - http://www.scopus.com/inward/record.url?scp=85098132874&partnerID=8YFLogxK
U2 - 10.1039/d0ta08815c
DO - 10.1039/d0ta08815c
M3 - Journal article
AN - SCOPUS:85098132874
SN - 2050-7488
VL - 8
SP - 26130
EP - 26138
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 48
ER -