Coherent Design of CoAl Layered Double Hydroxide-Derived Co3O4 Cubes as a Competent Electrocatalyst for Water Splitting and Urea Electrolysis

Here, we studied the electrocatalytic activity of a CoAl-LDH-derived Co3O4 cube, which has an amplified electrochemical surface area and conductivity, which in turn escalates the electrochemical performance. The cubic Co3O4 promotes OER, HER, and UOR with significantly lower potentials of 1.51, 0.192, and 1.36 V at a 10 mA cm–2 current density; this electrocatalytic performance addresses the kinetic challenges associated with electrolytic reactions in an effective manner. Moreover, we assembled a full-cell water electrolyzer employing the Co3O4 cube//Co3O4 cube as both the cathode and anode, achieving various current densities of 10, 20, 50, and 100 mA cm–2 with corresponding cell voltages of 1.49, 1.72, 1.83, and 1.95 V. In addition, synthesized Co3O4 cubes demonstrate excellent urea electrolytic performance, maintaining stable voltages of 1.40, 1.47, 1.57, and 1.70 V under similar current densities. Notably, the Co3O4 cube electrocatalyst exhibited sustained stability over 24 h, maintaining a voltage of 1.72 V in alkaline 1.0 M KOH solution and 1.47 V in alkaline 1.0 M KOH + 0.5 M urea solution, showing a reduction of 275 mV compared to the overall water electrolyzer at a current density of 20 mA cm–2.