Ni, N‐codoped NiMoO4 grown on 3D nickel foam as bifunctional electrocatalysts for hydrogen production in urea‐water electrolysis

In this study, Ni, N-NiMoO 4 /NF, and other compared materials are synthesized as bifunctional electrocatalysts for hydrogen evolution (HER) and urea oxidation reactions (UOR). The results of characterizations and tests show that the electrocatalytic performance of Ni, N-NiMoO 4 /NF is higher than those of NiMoO 4 •xH 2 O/NF, Ni-NiMoO 4 •xH 2 O/NF, and N-NiMoO 4 /NF, which may be caused by the synergy between Ni, N, and NiMoO 4 . The introduction of N and Ni increases the wettability and adsorption of the material, which also increases the conductivity and catalytic performance of the material. Furthermore, it is found that the electrodeposition time of metallic nickel (Ni, N-NiMoO 4 /NF-x ( x =10, 20, 30 min)) can affect the catalytic performances of Ni, N-NiMoO 4 /NF. The results show that the Ni, N-NiMoO 4 /NF-20 shows the best bifunctional electrocatalytic activity among all prepared samples, with 176 mV towards HER and 1.444 V towards UOR at 100 mA•cm −2 , demonstrating its potential in a practical application as a bifunctional electrocatalyst for hydrogen production in urea-water electrolysis.