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

Abstract

Identifying high‐performance non‐precious metal‐based catalysts at the cathode is a major challenge for future practical applications. Herein, a soft‐template route through a self‐assembly arrangement of sulfur sources was successfully developed, facilitating the anion exchange. In addition, compared with pristine cobalt disulfide synthesized without templates, the cobalt disulfide prepared using the new method 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 eg orbitals was verified for the cobalt disulfide after shrinkage, which was the main factor for enhancing the intrinsic activity of the catalyst. Besides the microscopic morphologic structure, elementary composition, and the valence state of the elements, the possible growth process of the cobalt disulfide was also discussed in detail. As catalyst for the oxygen reduction reaction, CoS2 showed a similar half‐wave potential (0.81 vs. 0.84 V for Pt/C) and higher diffusion‐limiting current density (reaching 5.33 vs. 5.19 mA cm−2 for Pt/C) than a commercial Pt/C catalyst. Hence, our results provide a rational design direction for this type of catalysts.

Heterostructuring cobalt sulfide with highly oxophilic 1T-tungsten sulfide for durable and efficient oxygen electrocatalysis

“…*OOH, *O, *OH, where * represents catalytically active centers) that are closely dependent on the orbital filling of transition-metal centers is considered as an indicator of ORR performance. 47–49 As reported previously, cobalt centers in the Co–S configuration show a weaker affinity towards oxygenated intermediates than a promising value, 50–52 agreeing well with those of spinel cobalt oxide and Co–N–C catalysts. 53–56 Growing 1T-WS 2 nanoplatelets with a metallic feature at the CoS surface can induce the electron transfer into CoS and strengthen the affinity of oxygenated intermediates, as manifested by a higher desorption temperature in O 2 -TPD plots of CoS/WS 2 /CNC-1 than that of CoS/CNC, thereby enhancing the ORR performance.…”

Revealing the intrinsic peroxidase-like catalytic mechanism of O-doped CoS2 nanoparticles

“…These include excellent biological safety, 23 photothermal, 23 and catalytic properties. 24 Notably, its catalytic properties can be rationally modulated by various strategies such as defect engineering, 25,26 lattice shrinking, 27 and integration with other compounds. 19,28 These unique properties made it a promising nanozyme with broad applications in biomedical and environmental fields.…”