Interface engineering of Fe-Sn-Co sulfide/oxyhydroxide heterostructural electrocatalyst for synergistic water splitting
Siyu Chen, Ting Zhang, Jingyi Han, Hui Qi, Shihui Jiao, Changmin Hou, Jingqi Guan
Abstract
To realize large-scale hydrogen production by electrolysis of water, it is essential to develop non-precious metal catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Here, we fabricate Sn-, Fe-, and Co-based sulfide/oxyhydroxide heterostructural catalyst on nickel foam (FeSnCo<sub>0.2</sub>S<em><sub>x</sub></em>O<sub><em>y</em></sub>/NF) by solvothermal method. The FeSnCo<sub>0.2</sub>S<em><sub>x</sub></em>O<em><sub>y</sub></em>/NF requires low overpotentials of 48 and 186 mV at 10 mA·cm<sup>–2</sup>, respectively, for HER and OER. When it is assembled into an electrolytic cell as a bifunctional electrocatalyst, it only needs 1.54 V to reach 10 mA·cm<sup>–2</sup>, far better than IrO<sub>2</sub>||Pt/C electrolyzer. The formation of sulfide/hydroxide heterostructural interfaces improves the electron transfer and reduces the reaction energy barrier, thus promoting the electrocatalytic processes.