MoO3/V2O5/Ni(OH)2 with multiple heterojunction interfaces for the hydrogen preparation from urea-containing wastewater

Compared to a single heterostructure, constructing multiple heterojunction interfaces to enhance bifunctional catalytic activity still faces challenges. Herein, a nanoflower-like electrocatalyst with multiple heterojunction interfaces, which consists of MoO3, V2O5, and Ni(OH)2 in-situ grown on nickel foam, is prepared through a one-step hydrothermal method (MoO3/V2O5/Ni(OH)2/NF, named MVN/NF). The MVN/NF exhibits superior catalytic performance, attributable to enhanced electron transfer facilitated by numerous heterojunction interfaces, a substantial active specific surface area, and a self-supported architecture. It requires low potentials for hydrogen evolution reaction, urea oxidation reaction, and overall urea electrolysis of 81 mV, 1.351 V, and 1.450 V (vs. RHE), respectively, to reach a current density of 10 mA cm−2. By cutting the material into a large-scale electrode for use in an alkaline electrolyzer, its Faraday efficiency was 90.0%, and the urea decomposition rate reached 45.1%. This work offers broad application prospects for the realization of large-scale hydrogen production and the decomposition of urea-containing wastewater.