Since the inception of the NEC2-MABs project, significant progress has been made toward achieving the outlined research objectives and work packages. The initial phase focused on Work Package 2 (WP2), involving the computational study and selection of high-entropy alloy (HEA) nanomaterials (NMs) for enhanced electrocatalysis (Research Objective 2, RO2). Density Functional Theory (DFT) calculations were performed to predict the catalytic activity of various transition metal-based HEAs. This led to the identification of Ni-rich CuZrN@NiCo layered double hydroxides (LDHs) as promising candidates due to their synergistic effects and high active surface areas.
Building on these findings, Work Package 3 (WP3) centered on the experimental synthesis of the selected materials (RO3). A co-precipitation method was employed to vertically grow NiCo LDHs on one-dimensional CuZrN nanowires (NWs), optimizing the Ni ratio to enhance catalytic performance. Hydrothermal treatment facilitated the transformation of NWs into porous nanotubes (NTs) through nanoscale Galvanic Replacement (GR) and bulk diffusion phenomena. This process resulted in engineered 3D nanoarchitectures with increased active surface areas and improved electron transport pathways.
In Work Package 4 (WP4), the focus shifted to structural and morphological evaluations to tune the functional characteristics of the synthesized NMs (RO4). Advanced characterization techniques such as X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy-Dispersive X-ray Spectroscopy (EDAX) were utilized. These analyses confirmed the successful synthesis of the targeted nanocomposite materials and provided detailed insights into their structural integrity, morphology, and elemental composition.
Electrochemical evaluations using cyclic voltammetry (CV) techniques demonstrated that the Ni-rich CuZrN@NiCo LDHs exhibit superior Oxygen Evolution Reaction (OER) and Oxygen Reduction Reaction (ORR) performances compared to benchmark catalysts like RuO2 and Pt/C in alkaline media. The materials showed lower overpotentials and higher current densities, indicating enhanced catalytic activity and stability—addressing key scientific challenges outlined in the project.
Preliminary steps were also taken in Work Package 5 (WP5) to fabricate cathode materials for application in Zn-air batteries (RO5). A laboratory-scale model was established to evaluate energy storage performance, with initial tests showing promising results in terms of open-circuit voltage stability and energy density.
Throughout this period, the researcher engaged in extensive training activities, aligning with Work Package 1 (WP1) and Research Objective 1 (RO1). New practical skills were acquired in advanced material synthesis, electron microscopy, and X-ray diffraction techniques. Training on project management, communication, and leadership skills was also undertaken, enhancing the capacity to lead independent research initiatives.
In summary, the project has successfully advanced through the initial work packages, achieving significant milestones in the synthesis, characterization, and performance evaluation of advanced nanocomposite materials for cathode catalysis in metal-air batteries. The main results achieved so far lay a solid foundation for the subsequent phases of the project and contribute to advancements in energy storage technologies.
