Synthesis of Lattice‐Contracted Cobalt Disulfide as an Outstanding Oxygen Reduction Reaction Catalyst via Self‐assembly Arrangement

Abstract

High‐performance non‐precious metal‐based catalysts at the cathode is a major challenge in future practical applications. Herein, a developed soft‐template route successfully achieved a self‐assembled arrangement of sulfur sources, facilitating the anion exchange. Meanwhile, compared with pristine cobalt disulfide without templates, the prepared cobalt disulfide presented a lattice shrinking phenomenon due to the hindrance of cobalt hydroxide crystal‐cell. Based on x‐ray absorption spectroscopy (XAS) and density functional theory (DFT) calculation, increased occupancy of e g orbitals was verified for the cobalt disulfide after shrinkage, which was the main factors for enhancing the intrinsic activity of catalysts. Besides the microscopic morphologic structure, elementary composition, the valence state of the element, and the possible growth process of the cobalt disulfide was also discussed in detail in this paper. For electrocatalytic activity, the O‐CoS 2 established a close half‐wave potential (reached 0.81 V, vs. Pt/C 0.84) and higher a diffusion‐limiting current density (reached 5.33 mA⋅cm ‐2 , vs. Pt/C 5.19) than commercial Pt/C catalysts. So, our results provided a rational designing direction for the kind of catalysts.