Scalable room-temperature synthesis of NiFe oxyhydroxide tailored with S atoms for enhanced oxygen evolution in alkaline seawater and domestic sewage

Abstract

Developing facile and scalable method to prepare oxygen evolution reaction (OER) catalysts which is suitable for industrial water electrolysis at large operating current densities is vital for green hydrogen production, but still remains a great challenge. Herein, we developed a one-step method to in situ fabricate S-doped NiFe oxyhydroxide (S–Ni(Fe)OOH) ultrathin nanosheet on Ni foam at room temperature, which is suitable for scaled up production, by which a electrode with 500 cm2 can be facilely prepared. The prepared S–Ni(Fe)OOH shows excellent OER stability and activity in 5 M KOH, alkaline sewage and seawater, which only need 198, 275 and 284 mV to reach 500 mA cm−2, respectively. Theoretical calculations indicated that the incorporation of S modulates the chemisorption of oxygen-containing intermediates and facilitates the evolution from ∗OH to ∗O, thus enhance the intrinsic OER activity of S–Ni(Fe)OOH. The electrolyzer based on S–Ni(Fe)OOH can reach a current density of 100 mA cm−2 at a small cell voltage of 1.56 V in 1 M KOH, much smaller than the benchmark catalyst Pt/C||IrO2(1.87 V). This work provides a facile method to prepare highly efficient catalyst for alkaline sewage and seawater oxidation, which could provide references to the development of catalyst for practical hydrogen production.