Enhanced hydrogen production via catalytic water and urea oxidation in a hybrid acid-base electrolytic cell with NiFe-LDH/NiMoO4/NF

The construction of crystalline-amorphous coupling structure is one of the effective strategies to enhance the performance of oxygen evolution reaction (OER) and urea oxidation reaction (UOR). Herein, NiFe-LDH/NiMoO 4 /NF with high oxygen evolution and urea oxidation performance was successfully prepared by electrodeposition of amorphous substances on the crystalline precursor of hydrothermal synthesis. Remarkably, the NiFe-LDH/NiMoO 4 /NF displays exceptional electrocatalytic performance for OER and UOR, with a potential of only 1.57 V vs. RHE at 100 mA cm −2 and the Tafel slope of 54.4 mV dec −1 for OER, high UOR activity with a potential of 1.45 mV@100 mA cm −2 and the Tafel slope of 20.4 mV dec −1 in 1.0 M KOH with 0.33 M urea solution. In a hybrid acid-base electrolysis system for urea oxidation-assisted H 2 production using NiFe-LDH/NiMoO 4 /NF as the anode electrode and Pt/C/NF as the cathode electrode, the process requires a cell voltage of only 0.55 V vs . RHE at 10 mA cm −2 . Moreover, this hybrid acid/base system demonstrates stable operation for 110 h with minimal attenuation at a current density of 100 mA cm −2 . These results indicate a facile strategy for the design of electrodes with crystalline-amorphous coupling structures for energy conversion.