Electrolysis is a promising method for storing energy in the form of hydrogen fuel, which is of great importance for the application of renewable energy. Due to the sluggish anodic reaction of water splitting, exploration of high-efficiency and cost-effective electrocatalysts enabling low driving potential for hydrogen generation is highly desirable. Here, we report a bifunctional electrocatalyst consisting of two-dimensional NiCo-BDC nanosheet arrays coated with Ni-S thin layers, presenting promising catalytic activity and durability for oxygen evolution reaction (OER) and urea oxidation reaction (UOR). Impressively, this anode could reach a current density of 10 mA cm−2 at an overpotential of 229 mV in 1.0 M KOH for OER. For UOR, only a small potential of 1.31 V (vs. reversible hydrogen electrode) is required for driving a current density of 10 mA cm−2 in 1.0 M KOH with 0.33 M urea. Furthermore, a full electrochemical cell was constructed using the as-prepared catalyst as anode and the Pt/C as cathode. For overall water splitting, only a low potential of 1.53 V is required to gain a current density of 10 mA cm−2 in 1.0 M KOH, whereas the urea-mediated electrolysis cell demonstrates a lower operating potentials of 1.46 V at 10 mA cm−2. This work presents a solid step towards lowing the driving potential for hydrogen generation via water splitting.