POMs@ZIF-8 derived transition metal carbides for urea electrolysis-assisted hydrogen generation.

Employing the urea oxidation reaction (UOR) instead of the water oxidation reaction can not only decrease the theoretic hydrogen generation cell voltage in sustainable energy conversion but also eliminate urea pollution in water. Herein, we used a facile in situ trapping and pre-modification strategy to synthesize MoC@C and hybrid Ni/WC@C nanoparticles and employed the two materials as hydrogen evolution reaction and UOR catalysts, respectively, in an electrolytic cell. The resultant setup can achieve a catalytic current density of 20 mA cm -2 at a cell voltage of 1.5 V in alkaline solutions and maintain stability for at least 12 h in the same conditions.