Synergistic Effect of Co 9 S 8 and FeS 2 Inlaid on N-Doped Carbon Nanofibers toward a Bifunctional Catalyst for Zn–Air Batteries

作者：Lixin Sun, Shuhong Huang, Xinyan Zhao, Xinyan Zhao, Ling Li, Xiaohui Zhao, Xiaohui Zhao, Wenming Zhang · 发表于：Langmuir · 年份：2022 · DOI：10.1021/acs.langmuir.2c01882 · 被引用次数：15 · 研究领域：Advanced battery technologies research、Electrocatalysts for Energy Conversion、Advanced Battery Materials and Technologies

The development of economical and energy-efficient electrocatalysts is essential for the wide-scale application of secondary zinc–air batteries (ZABs). Herein, we prepared Co 9 S 8 and FeS 2 nanoparticles inlaid on N-doped carbon nanofibers (Co 9 S 8 -FeS 2 @N-CNFs), which were derived from the in situ growth of Fe-doped ZIF-67 nanosheet arrays on electrospun nanofibers and a subsequent sulfidation process. The Co 9 S 8 -FeS 2 @N-CNFs display excellent electrocatalytic performances for OER ( E j =10, 330 mV) and ORR ( E 1/2, 0.80 V) as well as a smaller charge and discharge gap (Δ E, 0.76 V) in KOH electrolyte, allowing it to be employed as an attractive air cathode bifunctional catalyst for secondary ZABs. The electrocatalytic performance of the composite materials (Co 9 S 8 -FeS 2 @N-CNFs) is obviously better than that of the single-component materials (FeS 2 @N-CNFs and Co 9 S 8 @N-CNFs). The improved catalytic performance is mainly attributed to the synergistic effect of the two transition-metal sulfides and the optimization of the structure. Furthermore, the peak power density of the assembled aqueous/solid-state ZABs based on Co 9 S 8 -FeS 2 @N-CNFs can reach 214 and 91 mW cm –2 with excellent stability, respectively, which outperforms the ones based on commercial precious-metal-based catalysts. We anticipate that our work will provide new inspiration for the design of MOF-derived sulfides as multifunctional catalysts.