Synergistically Interfaced Bifunctional Transition Metal Selenides for High‐Rate Hydrogen Production Via Urea Electrolysis

Abstract The realization of carbon‐neutral energy is regarded a prime challenge as the environment and energy have become two key issues facing modern society. Here, synergistically interfaced transition metal selenides are studied for hydrogen production via urea electrolysis with concurrent environmental treatment. Extremely low overpotentials of 210 mV, 250 mV, and 1.41 V vs. RHE were observed at 100 mA cm −2 for HER, OER and UOR, respectively with a 98.3 % faradaic efficiency. A notably low cell voltage of 1.6 and 1.84 V was required at 200 mA cm −2 for urea and water electrolysis, respectively along with a remarkably stable performance for 4 days. Additionally, A 1.45‐fold increase in H 2 production rate was observed for urea electrolysis [26.6 μmol min −1 ] when compared with water electrolysis [18 μmol min −1 ] decreasing the power consumption by 37 %. Real human urine electrolysis was conducted with excellent performance requiring a cell voltage of only 1.9 V at 200 mA cm −2 , attributed to the synergistic intermediate‐active site interaction, improved charge transfer capability, and slow surface transformation‐induced activation.