Water splitting requires nonprecious materials that can catalyze efficiently both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Here, we report the synthesis of mackinawite FeS nanosheets grown on iron foam, which can serve as an efficient pre-electrocatalyst for both HER and OER in alkaline media. During electrochemical HER testing, [email protected] [email protected] oxysulfide nanoparticles as the catalytically active phase are generated in situ on FeS nanosheets. During electrochemical OER testing, FeS nanosheets totally transform into porous amorphous FeO_x film that can mediate the OER efficiently. When assembled as the cathode and the anode in a single electrolyzer, the resulting Fe-based catalysts can give a good overall water-splitting output that outperforms the one obtained from a noble-metal-based Pt/C-IrO₂-coupled electrolyzer. These results provide new insights on the active sites of Fe-based catalysts as well as an impetus for further research on low-cost, iron-containing water-splitting electrocatalysts.

水分解需要非贵重的材料，这些材料可以有效催化氢气析出反应（HER）和氧气析出反应（OER）。在这里，我们报告了在泡沫铁上生长的马基钠铁矿FeS纳米片的合成，它可以用作碱性介质中HER和OER的有效预电催化剂。在电化学HER测试过程中，在FeS纳米片上原位生成了[电子邮件保护的] [电子邮件保护的]氧硫化物纳米颗粒作为催化活性相。在电化学OER测试过程中，FeS纳米片完全转变为多孔无定形FeO _x可以有效调解OER的电影。当在单个电解器中作为阴极和阳极组装时，所得的铁基催化剂可提供良好的总水分解输出，其性能优于从贵金属基Pt / C-IrO ₂耦合的电解器获得的水分解输出。这些结果为铁基催化剂的活性位点提供了新的见解，并为进一步研究低成本，含铁的水分解电催化剂提供了动力。