Developing low-cost electrocatalysts with excellent activity
and
durability in urea-assisted water splitting is urgently needed in
order to achieve sustainable hydrogen production. Herein, we in situ
synthesized a robust coupled heterostructured electrocatalyst (CoP/MoO2) on a nickel foam (NF) substrate and explored its electrocatalytic
performances in the hydrogen evolution reaction (HER), oxygen evolution
reaction (OER), and urea oxidation reaction (UOR). The overpotential
of CoP/MoO2/NF is found to be only 11 mV at 10 mA cm–2 during the HER process, which is significantly lower
than that of commercial Pt/C. Meanwhile, the UOR catalytic performance
of CoP/MoO2/NF indicates fast reaction kinetics, along
with a considerable low driving potential (1.26 V) compared to that
of the OER (1.51 V). In situ and ex situ techniques demonstrate that
these excellent electrocatalytic properties are mainly ascribed to
the effective synergistic coupled effect and strong electronic interactions
between single-component CoP and MoO2, which can tune electronic
states of Co and Mo, expose more active sites, enhance intrinsic catalytic
activity, and accelerate charge transfer. Moreover, when used in electrochemical
overall water splitting and urea-assisted water electrolysis, CoP/MoO2/NF can reach a current density of 10 mA cm–2 at only 1.46 and 1.32 V. This outperforms Pt/C||RuO2 and
numerous nonprecious metal electrocatalysts and maintains a stable
long-term electrolytic operation for 84 h. This work provides a promising
pathway for the development of efficient catalysts during urea-assisted
water electrolysis for hydrogen production.