Facilitating the Deprotonation of OH to O through Fe4+ -Induced States in Perovskite LaNiO3 Enables a Fast Oxygen Evolution Reaction.
Gaoliang FuWeiwei LiJia-Ye ZhangMengsha LiChangjian LiNing LiQian HeShibo XiDongchen QiJudith L MacManus-DriscollJun ChengKelvin Hongliang ZhangPublished in: Small (Weinheim an der Bergstrasse, Germany) (2021)
Aliovalent doping is widely adopted to tune the electronic structure of transition-metal oxides for design of low-cost, active electrocatalysts. Here, using single-crystalline thin films as model electrocatalysts, the structure-activity relationship of Fe states doping in perovskite LaNiO3 for oxygen evolution reaction (OER) is studied. Fe4+ state is found to be crucial for enhancing the OER activity of LaNiO3 , dramatically increasing the activity by six times, while Fe3+ has negligible effect. Spectroscopic studies and DFT calculations indicate Fe4+ states enhance the degree of Ni/Fe 3d and O 2p hybridization, and meanwhile produce down-shift of the unoccupied density of states towards lower energies. Such electronic features reduce the energy barrier for interfacial electron transfer for water oxidization by 0.2 eV. Further theoretical calculations and H/D isotope experiments reveal the electronic states associated with Fe4+ -O2- -Ni3+ configuration accelerate the deprotonation of *OH to *O (rate-determining step), and thus facilitate fast OER kinetics.
Keyphrases
- transition metal
- metal organic framework
- electron transfer
- density functional theory
- aqueous solution
- low cost
- molecular dynamics simulations
- room temperature
- molecular dynamics
- molecular docking
- structure activity relationship
- gene expression
- diabetic rats
- genome wide
- dna methylation
- high efficiency
- oxidative stress
- case control