In situ construction of pollen-petal-like heterostructured Co3O4-CeO2 on 3D FeNi3 foam as a bifunctional catalyst for overall water splitting

The rational design of admirably high-efficiency and relatively stable non-noble metal electrocatalysts is vitally important for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), particularly as bifunctional catalysts for overall water splitting. Herein, via a facile one-pot hydrothermal approach, high-performance bifunctional catalysts of Co3O4-CeO2 with pollen-petal-like heterostructures are synthesized in situ on 3D FeNi3 foam (FNF) (denoted as Co3O4-CeO2@FNF). In a 1.0 M alkaline aqueous solution of KOH, the designed Co3O4-CeO2@FNF with a large surface area exhibits both outstanding HER and OER activities, with an ultralow overpotential of 53.8 and 236 mV at 10 mA cm(-2), respectively. Additionally, a standard two-electrode system fabricated by employing Co3O4-CeO2@FNF as both the cathode and anode shows an overpotential of 1.59 V at 10 mA cm(-2) and moreover retains 93% of the activity after a 70 h long-term stability test. Moreover, the electron transportation is accelerated due to the increased density of states across the Fermi level resulting from oxygen vacancy doping, which further endows Co3O4-CeO2@FNF with outstanding catalytic performance. Furthermore, it should be noted that the designed catalysts could be manufactured on a large scale, which further envisions their promising commercial utilization for overall water splitting.

Automated summary

The Co3O4-CeO2@FNF bifunctional catalyst, synthesized via a facile one-pot hydrothermal approach, shows outstanding performance for both HER and OER in alkaline conditions, with potential commercial applications for overall water splitting.