Electrochemical water splitting is an attractive technique to produce renewable hydrogen gas. However, considerable challenges remain before the catalytic anodic oxygen evolution reaction (OER) can occur at a satisfactory rate due to its sluggish kinetics, thus hampering the overall efficiency of this technology. Urea electrolysis provides opportunities for energy-conserving hydrogen production and the concurrent remediation of urea-enriched sewage water. Therefore, developing advanced electrocatalysts with a reduced cost and improved efficiency for the urea oxidation reaction (UOR) is key to the implementation of this technique. Herein, we present a three-dimensional (3D) self-supported nickel phosphide/Ni foam electrode (P-NF) that can be prepared by adopting a straightforward low-temperature phosphorization treatment of commercially available Ni foam. As a result, compared with the pristine Ni foam, the as-prepared 3D P-NF catalyst presents obviously enhanced activity for the electrocatalytic UOR, and a small potential of 1.32 V (versus the reversible hydrogen electrode (RHE)) is required to achieve a current density of 10 mA cm(-2). When the P-NF electrode is employed to catalyze the hydrogen evolution reaction (HER), it shows equally satisfactory performance. Moreover, a two-electrode electrolyzer system made of the as-obtained P-NF as the bifunctional electrocatalyst can deliver 10 mA cm(-2) at a cell voltage of only 1.37 V with remarkable operational stability.