One-step achievement of Fe-doped and interfacial Ru nanoclusters co-engineered Ni(OH)₂ electrocatalyst on Ni foam for...

The creation of inexpensive, high-performance catalysts to reduce the overpotential of the oxygen evolution reaction (OER) process is critical for the electrolysis of water for hydrogen production. Therefore, we applied a one-step hydrothermal method using cation exchange reaction (CER) to prepare Fe-doped and interfacial Ru nanoclusters co-engineered Ni(OH)₂ nanosheets directly grafted on Ni foam (Ru@Fe-Ni(OH)₂/NF) for OER process. Results of electrochemical tests reveal that Ru@Fe-Ni(OH)₂/NF has excellent OER activity, and its overpotential (η) is only 266.4 mV when the current density is 50 mA cm^-2 in 1 M KOH solution, even lower than that of commercial OER catalyst RuO₂ (355 mV). The Tafel slope also decreases from 133.8 mV dec^-1 for pristine Ni(OH)₂/NF material to 24.1 mV dec^-1 for Ru@Fe-Ni(OH)₂/NF, indicating the higher charge transfer rates and fastest kinetics for water oxidation. At an overpotential of 300 mV the optimal turnover frequency (TOF) of 0.062 s^-1 for Ru@Fe-Ni(OH)₂/NF is achieved compared to that of Ni(OH)₂/NF (0.014 s^-1, NN), demonstrating the fast reaction kinetics of the as-prepared electrocatcalyst. After 24 h stability test, the catalytic activity of Ru@Fe-Ni(OH)₂/NF was only attenuated by 2 %, showing excellent OER stability and durability. Our results show that we have successfully developed an efficient OER catalyst for green and efficient electrocatalytic hydrolysis to produce H₂ and O₂, providing a promising method for clean H₂ production.