Improved oxygen evolution reaction performance in Co0.4Mn0.6O2 nanosheets through Triple-doping (Cu, P, N) strategy and its application to Zn-air battery

• Published in: Applied catalysis. B, Environmental Environmental, 2023-01, Vol.320, p.122023, Article 122023
• Main Authors: Li, Ying, Talib, Shamraiz Hussain, Liu, Dongqing, Zong, Kai, Saad, Ali, Song, Zhaoqi, Zhao, Jie, Liu, Wei, Liu, Fude, Ji, Qianqian, Tsiakaras, Panagiotis, Cai, Xingke
• Format: Article
• Language: English
• Subjects: CV activation; OER; Surface reconstruction; Ternary Cu0.1Co0.3Mn0.6O2; Zinc-Air battery
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2022.122023

In this work, we successfully synthesized bimetallic transition oxides into two-dimensional nanosheets, which expose all the catalytic sites on the surface. Then, Cu, N, and P elements were rationally doped inside the as prepared Co0.4Mn0.6O2 nanosheets to activate the Co/Mn catalytic sites. It is found that the resulting N/P-Cu0.1Co0.3Mn0.6O2/CNTs composites show an overpotential η10 of 290 mV for OER, much lower than the value measured using the original Co0.4Mn0.6O2/CNTs (463 mV). Meanwhile, N/P-Cu0.1Co0.3Mn0.6O2/CNTs also show decent performance with a half potential (E1/2) of 0.82 V vs RHE for ORR, i.e., a 702 mV voltage difference for OER and ORR, much lower than other transition metal oxide catalysts. By using N/P-Cu0.1Co0.3Mn0.6O2/CNTs as a cathodic catalyst for ZAB, we measured superior performance, with a peak power density of 108.1 mW cm−2 and stable operation for over 200 h at 10 mA cm−2, better than IrO2-Pt/C-based ZAB. [Display omitted] •Firstly we successfully synthesized bimetallic transition oxides (Co0.4Mn0.6O2) into two-dimensional nanosheets.•Then, Cu, N, and P were rationally doped inside the Co0.4Mn0.6O2 nanosheets to activate the Co/Mn catalytic sites.•By doping Cu, N, P into Co0.4Mn0.6O2/CNTs to form N/P-Cu0.1Co0.3Mn0.6O2/CNTs, the OER overpotential was 292 mV.•Employing N/P-Cu0.1Co0.3Mn0.6O2/CNTs, the ZAB exhibited higher peak power density and better stability.•DFT simulation showed that the increased OER activity is due to the considerable charge transfer from Co atom.