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

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 eta 10 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.

Automated summary

In this work, bimetallic transition oxides were successfully synthesized into two-dimensional nanosheets, which expose all the catalytic sites on the surface. Cu, N, and P elements were then doped inside the nanosheets to activate the catalytic sites. The resulting composites show improved catalytic performance for OER and ORR, as well as superior performance as a cathodic catalyst for ZAB.