In-situ synthesis of N/S co-doped Cu-based graphene-like nanosheets as high efficiency electrocatalysts for oxygen reduction reaction

Abstract

Heteroatom-doped transition metal electrocatalysts supported on carbon materials are widely-recognized as the promising catalysts for oxygen reduction reaction (ORR). Here, we describe the one-pot method of preparing the Cu-based PAT1-Cux/KB catalyst with Cu/N/S doped graphene-like nanosheets. For the obtained catalyst, Cu2+ ions catalyzed the polymerized 2-aminothiazole organic monomers into nanosheet and simultaneously in-situ doped Cu, N, S atoms into the carbon matrix. The amount of Cu2+ ions affected the geometry structure, as well as the formation of Cu–N structure and C–S–C bond of PAT1-Cux/KB catalyst. Cu2S crystals with ORR catalytic ability were also generated in the catalysts. The Cu–N structure in the catalyst regulates the d-electron density of inert copper through the synergistic effect of electronic connection between copper and nitrogen atoms. N and S doped in the carbon skeleton changes the spin density and charge distribution of near carbon atoms. Therefore, PAT1-Cu0.33/KB catalyst with graphene-like nanosheets, Cu–N structure, C–S–C bond, and Cu2S crystals exhibits excellent activities with E1/2 = 0.84 V and high limit-current density of 5.25 mA cm−2 for ORR.