Engineering NiF3/Ni2P heterojunction as efficient electrocatalysts for urea oxidation and splitting

Exploring highly efficient and ideal stability electrocatalysts for urea oxidation reaction (UOR) is highly desired to achieve hydrogen production by an economic way. Herein, a novel flexible, self-supported NiF3-Ni2P heterostructure in-situ grown on carbon cloth (NiF3/Ni2[email protected]) is controllable synthesized by hydrothermal and subsequent successive fluorination-phosphorization method. The as-obtained optimized NiF3/Ni2[email protected] is featured by large amounts of high valent Ni3+ active sites, reconfigured local charge density, superior hydrophilic surface and mesoporous property. Thanks to these merits, the heterojunction electrode demonstrates advanced UOR performance compared to pure NiF3@CC and Ni2[email protected], merely needs a potential of 1.36 V vs. RHE to deliver a current density of 10 mA cm−2 and keeps the catalytic activity after 5,000 cyclic voltammetry tests. Significantly, NiF3/Ni2[email protected] hybrid can be utilized as bi-functional catalysts for UOR and water reduction (HER). A symmetrical urea electrolyzer constructed by NiF3/Ni2[email protected] as anode and cathode offers 50 mA cm−2 at a potential of 1.83 V, and can work continuously for more than 10 h. This work provides an advanced UOR electrocatalyst and gives great promising for designing heterojunction catalysts for H2 generation in a more economic way.