One-step electrodeposition synthesis of amorphous NiCoFe(OH)x/NF as an efficient catalyst for urea-assisted overall water splitting

An environmentally friendly method of producing hydrogen is electrocatalytic water splitting, but the high theoretical potential of the anode's OER (1.23 V vs. RHE) restricts the efficiency of hydrogen production. Therefore, using the urea oxidation reaction (UOR, theoretical potential of 0.37 V vs. RHE) in place of the OER can significantly increase the efficiency of hydrogen production. Here, we grow the hydroxide layer of Ni-Co-Fe directly on NF by one-step electrodeposition and obtain the best catalyst by regulating the elemental ratio of Co and Fe. Through tests, it is found that NiCoFe(OH)x/NF(Co: Fe=3: 1) exhibits the best electrocatalytic performance, and the required potential is only 1.24 and 1.30 V when the current density reaches 10 and 50 mA cm−2 in the UOR process, which is 170 and 140 mV lower than the OER overpotential under the same conditions, showing a more advantageous anodic catalytic effect. At the same time, integral water decomposition in an electrolyte of 1 M KOH adds with 0.5 M urea also shows more favorable catalytic activity and stability. The NiCoFe(OH)x/NF(Co: Fe=3: 1) plays an important role in improving the efficiency of hydrogen production by water splitting through simple electrodeposition, and has sustainable development prospects.