The TM-LDH project's research focuses on generating and understanding novel two-dimensional layered double hydroxide (LDH) materials, as well as their integration with conductive nanostructures like MXene. The objective was to create efficient, corrosion-resistant, and noble-metal-free electrocatalysts that could drive water splitting processes in alkaline and saltwater conditions. The research began with the synthesis of a variety of transition-metal LDH materials incorporating cobalt, zinc, and chromium, followed by surface modification and compositional adjustment to improve electronic conductivity and catalytic activity. These materials were coupled with Mo2TiC2 MXene to generate CoZnCr@MXene heterostructures. This offered an interconnected network for quick electron transport and increased endurance under severe saltwater conditions. Advanced characterisation technologies such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning and transmission electron microscopy (SEM/TEM), and electrochemical impedance spectroscopy (EIS) were used to conduct thorough structural, chemical, and electrochemical studies. These results demonstrated the effective production of homogeneous, well-defined nanostructures with a large electrochemical surface area and robust interfacial bonding between the LDH and MXene components. The CoZnCr@MXene catalyst produced excellent results in both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in alkaline and seawater electrolytes. It obtained overpotentials of just 45 mV (HER) and 20 mV (OER) at 10 mA cm⁻² in alkaline medium, greatly surpassing commercial noble-metal standards such as Pt/C and RuO2. Importantly, the catalyst remained active and stable even in saturated NaCl solutions, exhibiting exceptional resistance to chloride-induced corrosion. The material was successfully incorporated into an anion exchange membrane (AEM) electrolyzer, achieving 500 mA cm⁻² at 1.72 V and an efficiency of 77.8%, exceeding industrial-scale alkaline seawater electrolysis objectives. The electrolyzer ran continuously for more than 16.8 days with no deterioration, demonstrating its long-term reliability under actual operating circumstances. The cost of hydrogen generation was predicted to be 0.86 USD per gallon of gasoline equivalent, which is significantly lower than worldwide objectives for renewable hydrogen. To supplement the experimental results, density functional theory (DFT) simulations were used to better understand the role of MXene inclusion at the atomic level. The calculations demonstrated improved charge transfer, optimized hydrogen adsorption energy, and decreased energy barriers for oxygen evolution, corroborating the reported high catalytic activity. Overall, the TM-LDH project made a substantial scientific contribution by proving a long-lasting, efficient, and scalable electrocatalyst for seawater-based hydrogen generation. It also provided new insights into interface engineering and electrical tuning in layered 2D materials. These findings provide the groundwork for the next generation of sustainable materials for green hydrogen production and electrochemical energy storage.
