This work describes four integrated studies focused on enhancing the comprehension and efficiency of electrocatalysts for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). First, a series of MIL-101-Al/NF electrodes are synthesized, revealing a synergistic interaction between nickel and aluminum, and demonstrating the influence of different organic ligands (TPA, NH
2-TPA, OH-TPA) on surface morphology, crystal structure, and UOR performance. The MIL-NiAl/NF electrode achieved an onset potential of 1.372 V vs. RHE at 10 mA/cm
2 and a current density of 432 mA/cm
2 at 1.623 V vs. RHE. Second, comprehensive evaluations of the Ni/SiO2-C electrode are conducted, showcasing excellent UOR performance in a 1 mol/L KOH and 0.1 mol/L urea electrolyte, with a low overpotential of 118 mV at 10 mA/cm
2 and a Tafel slope of 10.89 mV/dec. The electrode demonstrated a current density of 279.2 mA/cm
2, outperforming the Ni@carbon electrode by 4.9 times. Third, highly efficient Al-P-C/NF freestanding electrodes are synthesized via an impregnation method, highlighting the synergetic effects of Ni-Al and the pivotal role of Al-O-P in enhancing electrocatalytic activity. The Al-P-C/NF electrode achieved a peak current density of 314.3 mA/cm
2 at 0.6 V vs. Ag/AgCl, representing a 7.8-fold increase over bare nickel foam. Finally, the HER performance of the Al-P-C/NF electrode is explored, demonstrating a Faraday efficiency of 96.55% at 200 mA/cm
2 and an onset potential of 203 mV at 100 mA/cm
2. While the HER performance is modest, the electrode's capabilities indicate its potential applicability in various electrochemical processes. Overall, this research contributes valuable insights into the design and optimization of electrocatalysts for sustainable energy applications.
| Date of Award | 2026 |
|---|
| Original language | English |
|---|
| Awarding Institution | - The Hong Kong University of Science and Technology
|
|---|
| Supervisor | Xijun HU (Supervisor) |
|---|