Cerium-incorporated Ni2P nanosheets for enhancing hydrogen production from overall water splitting and urea electrolysis

Hydrogen production from water splitting is a green and efficient technology for storing clean energy. Herein, cerium-incorporated Ni2P nanosheets are designed as trifunctional electrocatalysts to generate hydrogen by hydrothermal self-oxidation of surface nickel foam (NF) in pure water to in-situ form Ni(OH)2 nanosheets, followed by incorporation of Ce and phosphorization. The prepared material exhibits excellent electrocatalytic performance in hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and urea oxidation reaction (UOR). When the current density is 100 mA cm-2, the UOR potential of Ce-Ni2P is 1.473 V lower than that in the OER (1.731 V), suggesting a great potential to replace the sluggish OER for overall water splitting. Moreover, the Ce-Ni2P/NF can be applied to the electrochemical treatment of real urine electrolysis with similar performance to the urea electrolysis. Such remarkable performance is attributed to the incroporation of Ce with Ce3+/Ce4+ redox pairs, which can not only provide abundant reactive sites by the charge transfer appearance of defect sites, but also offer an effective buffering space for the pre-oxidation process from Ni2+ to Ni3+. It is thus beneficial for overall water splitting and coupled urea electrolysis, providing a promising candidate for urine wastewater treatment and clean energy production. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, cerium-incorporated Ni2P nanosheets were designed as electrocatalysts for hydrogen production from water splitting. The prepared material exhibited excellent electrocatalytic performance in hydrogen evolution, oxygen evolution, and urea oxidation reactions. It shows great potential for overall water splitting and urine wastewater treatment.