Two-dimensional (2D) materials provide high surface-to-volume ratios, short charge-transport pathways and large densities of accessible surface sites, making them particularly attractive for electrocatalysis. However, most elemental metals do not possess intrinsically layered crystal structures, making the direct synthesis of ultrathin, free-standing metallic nanosheets challenging. Indium (In) is particularly interesting because of its catalytic activity toward selective reactions including electrochemical CO₂ reduction. Recent studies have demonstrated highly active 2D metallic indium prepared through electrochemical conversion of specially synthesised coordination-polymer precursors. In parallel, molten indium spontaneously forms an atomically thin oxide skin through self-limiting surface oxidation, and this skin can be exfoliated to produce large-area In₂O₃ sheets only a few nanometres thick. Despite these advances, the possibility of using the unique liquid-metal interface as a direct synthetic platform for producing 2D metallic or metal-rich indium nanosheets remains comparatively unexplored. This project will investigate new synthetic strategies for converting liquid-metal-derived 2D indium oxide skins into ultrathin indium-based sheets while preserving their two-dimensional morphology. Approaches including controlled chemical, electrochemical and/or thermal reduction will be explored to manipulate the oxidation state and composition of the exfoliated sheets, with particular attention to preventing collapse, agglomeration or dewetting of the ultrathin structure during conversion. The resulting materials will be characterised using electron microscopy, AFM, X-ray diffraction and surface spectroscopic techniques to study processing conditions, sheet thickness, oxidation state, defects and surface chemistry. The project therefore addresses an important materials-processing gap between the established liquid-metal synthesis of 2D indium oxides and the emerging electrocatalytic potential of 2D metallic indium, while providing the candidate with experience spanning liquid-metal processing, 2D materials, advanced characterisation and electrochemistry.
School
Biomedical Engineering
Research Area
Materials science and engineering | Environmental applications | Inorganic chemistry
Suitable for recognition of Work Integrated Learning (industrial training)?
No
- Research environment
- Expected outcomes
- Supervisory team
- Reference material/links
The project will be based in the School of Biomedical Engineering at UNSW and supervised by Dr Dorna Esrafilzadeh, whose expertise in liquid metals, low-dimensional materials and functional material systems will guide the development of the proposed 2D indium platform. The project will be conducted in close collaboration with the UNSW School of Chemistry, providing complementary expertise and access to electrocatalysis and materials-characterisation capabilities. The candidate will therefore have access to a broad range of laboratory resources, materials synthesis facilities, advanced characterisation techniques and electrochemical testing capabilities across Biomedical Engineering and Chemistry.
- Conventional reduction of ultrathin metal oxides can result in particle formation, sintering or loss of the original 2D morphology. Developing conditions that retain the nanosheet geometry while controlling the Indium reduction ratio could therefore establish a new pathway toward non-layered 2D metals. The project will aim to establish a reproducible synthesis–structure–property relationship and determine whether the resulting ultrathin In or In/In₂O₃ structures provide enhanced electrochemically accessible surface area, charge transfer and catalytic performance compared with conventional indium materials.
