Sulfur-modulated FeNi nanoalloys as bifunctional oxygen electrode for efficient rechargeable aqueous Zn-air batteries

硫调控FeNi纳米合金作为双功能氧电极的研究

Currently,FeNi nanoalloys have received considerable attention for the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)in rechargeable aqueous zinc(Zn)-air batteries(ZABs)because of their high content and good chemical stability.However,their poor electronic conductivity,small surface area,and sluggish activity seriously hinder their catalytic performance.Herein,S-modulated FeNi nanoalloys supported by hierarchically porous carbon(SFeNi/PC)are synthesized through the thermal treatment of metal-organic precursors for efficient bifunctional oxygen catalysis.S decoration endows S-FeNi/PC with a superior OER performance while maintaining an ORR performance that is comparable to that of Pt/C.Hence,S-FeNi/PC exhibits excellent bifunctional oxygen catalytic activity,outperforming the noble-metal-based composite catalysts of Pt/C and RuO_(2).Notably,the ZABs assembled with S-FeNi/PC exhibit high specific capacity(792 mA h g^(-1)),high peak power density(123.5 mW cm^(-2)),and remarkable durability for 700 charge/discharge cycles at 10 mA cm^(-2),which surpasses the performance of commercially available Pt/C-RuOand other catalysts in previously reported studies.This study will provide not only new bifunctional oxygen electrodes for efficient ZAB devices but also new insights into the design of FeNi-based materials for a wide range of catalytic applications.

当前,FeNi合金由于其含量丰富、化学稳定性好的优点,在锌-空气二次电池(ZABs)中的氧还原反应(ORR)和析氧反应(OER)方面受到了广泛的关注.然而,传统FeNi合金还具有导电性差、比表面积小、活性低等缺点,严重阻碍了它们的催化性能.我们通过对金属有机前驱体进行热处理,合成了以分级多孔碳为载体的S-调控FeNi纳米合金材料(S-FeNi/PC),以实现高效的双功能氧催化.S调控赋予了FeNi纳米合金优越的OER性能,同时还使材料保持了与Pt/C相当的ORR性能.因此,SFeNi/PC具有很好的双功能氧催化活性,优于商业的Pt/C和RuO_(2)贵金属基复合催化剂.值得注意的是,以S-FeNi/PC为电极组装的ZABs具有较高的比容量(792 mA h g^(-1))、高峰值功率密度(123.5mW cm^(-2)),以及在10 mA cm^(-2)电流密度下可700次放电/充电循环的优异耐久性,这些性能远高于商用Pt/C-RuO_(2)催化剂,甚至超过了许多先前报道的工作.我们相信这项研究不仅为高效的ZABs装置提供了新的双功能氧电极材料,而且为具有广泛催化应用前景的FeNi基材料的设计提供了新的见解.