Ultrafast Two-Step Synthesis of S-Doped Fe/Ni (Oxy)Hydroxide/Ni Nanocone Arrays on Carbon Cloth and Stainless-Steel Substrates for Water-Splitting Applications

Nonprecious and effective electrocatalyst development is an essential requirement for boosting water-splitting efficiency to obtain clean and sustainable fuels for future renewable energy demands. Herein, we reported an ultrafast and feasible strategy for constructing an S-doped bimetallic iron/nickel oxy(hydroxide) (S-(Fe/Ni)OOH) as a superior electrocatalyst for oxygen evolution reaction (OER). It is prepared by consequent electroplating of nickel nanocone arrays (NiNCAs) on carbon cloth (CC) and stainless-steel mesh (SSM) and then formation of S-(Fe/Ni)OOH layers on them by ultrafast one-step oxidation solution-phase method in the solution of Fe3+ and sodium thiosulfate at room temperature. The derived composite material [S-(Fe/Ni)OOH@NiNCAs on SSM and CC] exhibited high electrocatalytic activity toward OER as well as good durability. The electrochemical measurements demonstrate that S-(Fe/Ni)OOH@NiNCAs-CC and S-(Fe/Ni)OOH@NiNCAs-SSM can drive the benchmark current density of 10 mA cm–2 at low overpotentials of 248 and 245 mV and current density of 100 mA cm–2 at overpotentials of 327 and 312 mV with a Tafel slope of 77 and 65 mV dec–1, respectively. Their outstanding electrocatalytic performances are benefited from porous, highly exposed active sites, accelerated mass and electron transport, and synergistic effects. The prepared composite electrodes act better than most advanced priceless catalysts and noble commercial RuO2 catalysts. This work provides an effective and efficient approach to design porous architecture catalysts on a three-dimensional substrate (SSM and CC) with high performance for energy-relevant and electrocatalysis reactions.