In Situ/Operando observed Local Structural Distortions of CoFe-LDH by Ru-doping for efficient water Oxidation
Pandian Mannu1*, Ta Thi Thuy Nga2, Ta Thi Thuy Nga1, Yu-Cheng Huang3, Chao-Hung Du1, Wu-Ching Chou2, Chi-Liang Chen3, Jeng-Lung Chen3, Asokan Kandasami4, Chung-Li Dong1
1Physics, Tamkang University, New Taipei City, Taiwan
2Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
3TLS/TPS, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
4Department of Physics & Centre for Interdisciplinary Research, University of Petroleum and Energy Studies, Uttarakhand, India
* Presenter:Pandian Mannu, email:pandianphy@gmail.com
The development of an excellent, multifunctional electrocatalyst based on non-precious metals is critical for improving the electrochemical processes of the hydrogen evolution reaction, the oxygen evolution reaction, and even seawater splitting. This study demonstrates that incorporating Ru into CoFe-LDH facilitated the formation of rich oxygen vacancies (Vo), which promotes effective nitrate adsorption and activation in water electrolysis. Subsequently, In-situ/Operando Raman and X-ray absorption spectroscopy is used to explore the active sites in Ru@CoFe-LDH under OER, indicating that the oxygen vacancies were firstly filled with OH• in Ru@CoFe-LDH; facilitated the preoxidation of low-valence Co, and promoted the reconstruction/deprotonation of intermediate Co-OOH•/O-O. Ru@CoFe-LDH electrocatalysts show impressive HER, OER, and seawater splitting with low overpotentials of 57 mV, 210 mV, and 237 mV, respectively, at 10 mA cm-2. The Ru@CoFe-LDH||Ru@CoFe-LDH catalyst in 1 M KOH (water) and 1 M KOH + 0.5 NaCl (simulated seawater) acts as an anode, and the cathode delivers 1.43 V at 10 mA cm-2. A viable approach to creating an effective seawater splitting system involves synergistic engineering that exploits doping and oxygen vacancies.
Keywords: Oxygen evolution reaction, X-ray absorption spectroscopy, Oxygen vacancies, Seawater Splitting, Raman spectroscopy