Metal atom-doped Co3O4 nanosheets for Li-O2 battery catalyst: Study on the difference of catalytic activity

Abstract

As a new star in catalysts, single atom catalysts (SACs) show excellent catalytic activity for Li-O2 battery. However, the mechanism of SACs in Li-O2 battery remains a vague but crucial challenge. Hence, we synthesized a series of Co3O4 nanosheet array-supported single atom catalysts grown on carbon cloth (marked as MSA-Co3O4/CC, M = Ti, V, Cr, Mn, Fe, Ni, Cu, Zn), whose (MSA-Co3O4/CC) structural and physicochemical properties are similar, and used them as cathode catalysts for Li-O2 batteries. Experimental results show that the catalytic activity of MSA-Co3O4/CC doped with different metal atoms is different for Li-O2 battery. Compared with the original Co3O4/CC cathode, the catalytic activity of some MSA-Co3O4/CC is improved while that of others is decreased. Among them, NiSA-Co3O4/CC has the best catalytic activity for Li-O2 battery, while VSA-Co3O4/CC has the worst. Density functional theory (DFT) calculation revealed that the reaction barrier on the active sites and the interaction (adsorption energy and electron transfer) between the doped metal atoms and the key reactants are the main factors affecting the catalytic activity of different metal atoms doped MSA-Co3O4/CC. We believe that this universal preparation method is of great significance for the development of novel SACs. In addition, this work also provides an atomic-scale understanding of fundamental catalytic trends and mechanisms for studying SACs.