Rapid Synthesis of Various Electrocatalysts on Ni Foam Using a Universal and Facile Induction Heating Method for Efficient Water Splitting

Electrocatalytic water splitting for the production of hydrogen proves to be effective and available. In general, the thermal radiation synthesis usually involves a slow heating and cooling process. Here, a high-frequency induction heating (IH) is employed to rapidly prepare various self-supported electrocatalysts grown on Ni foam (NF) in liquid- and gas-phase within 1-3 min. The NF not only serves as an in situ heating medium, but also as a growth substrate. The as-synthesized Ni nanoparticles anchored on MoO2 nanowires supported on NF (Ni-MoO2/NF-IH) enable catalysis of hydrogen evolution reaction (HER), showing a low overpotential of -39 mV (10 mA cm(-2)) and maintaining the stability of 12 h in alkaline condition. Moreover, the NiFe layered double hydroxide (NiFe LDH/NF-IH) is also synthesized via IH and affords outstanding oxygen evolution reaction (OER) activity with an overpotential of 246 mV (10 mA cm(-2)). The Ni-MoO2/NF-IH and NiFe LDH/NF-IH are assembled to construct a two-electrode system, where a small cell voltage of approximate to 1.50 V enables a current density of 10 mA cm(-2). More importantly, this IH method is also available to rapidly synthesize other freestanding electrocatalysts on NF, such as transition metal hydroxides and metal nitrides.

Automated summary

Electrocatalytic water splitting for hydrogen production is proven to be effective using high-frequency induction heating to rapidly prepare various self-supported electrocatalysts. The synthesized materials show low overpotentials and stability in alkaline conditions, enabling efficient hydrogen evolution and oxygen evolution reactions.