Abstract
NiFe-based electrode materials exhibit great promise for next-generation efficient oxygen evolution reaction (OER) electrocatalysts in alkaline medium, but they are difficult to be scaled up for large-area fabrication and are lack of robust research under real industrial conditions. Here we present a rapid, room-temperature suifuration strategy that transforms stainless steel meshes into highly active and stable oxygen evolution electrodes. Such method is easy to be scaled up to produce square meter-sized stainless steel electrodes (1m x 1m) with NiFeCr-containing trimetal sulfides on the surface. In a standard three-electrode cell, the sulfurated stainless steel electrode exhibits 7.2 times higher OER activity than the corresponding stainless steel, and possesses remarkable catalytic stability for over 1000 h at the current density range of 100-200 mA cm~(-2). During the OER, the Cr and S species are demonstrated to be easily detached from the electrode surface, and the in situ formed γ-(Fe,Ni)OOH is found to be the electrocatalytic active phase. Furthermore, we integrate the sulfurated stainless steel electrode into an industrial alkaline electrolyzer as the anode (400 cm~2). Our results demonstrate that the electrolyzer based on the sulfurated stainless steel electrode exhibits a better catalytic activity than the electrolyzer based on the Raney nickel electrode, a widely-adopted electrode in commercial water-alkali electrolyzers, and delivers a catalytic current of c.a. 300 mA cm~(-2) for over 120 h under the industrial catalytic conditions (30% KOH, 80 °C).
NSTL