Design and Development of Sustainable, Low-Cost, High-Performance Nanomaterials for Thermoelectric and Solar Hydrogen Applications

Thermoelectric (TE) materials enable direct conversion of heat into electricity without moving parts or reliance on light; however, their widespread application is limited by low efficiency and the toxicity or high cost of many high-performance materials. A fundamental challenge arises from the strong interdependence between the Seebeck coefficient, thermal conductivity and electrical conductivity, which hold back simultaneous optimisation. In buildings, this limitation coincides with substantial heat losses through windows, motivating the development of integrated glazing systems that simultaneously reduce heat loss and harvest energy. This thesis addresses these challenges by developing high-efficiency, non-toxic, cost-effective, and scalable TE materials for semi-transparent glazing operating near room temperature. Accordingly, target materials were strategically selected, synthesized, and developed through simple, scalable methods including electrochemical deposition, SILAR and drop-casting. Nanostructuring, doping and deposition on fluorine doped tin oxide substrates were employed to partially decouple charge transport pathways, enabling enhanced Seebeck coefficients, reduce thermal conductivity while maintaining electrical conductivity. The materials were comprehensively characterised, and their functional properties were evaluated. The first class of materials explored was Al-doped ZnO nanorods exhibited strong n-type thermoelectric behaviour with a ZT of 1.37 at 340 K, while CuI showed p-type performance with a ZT of 0.72 at 340 K. Integration into a thermoelectric glazing (TEGZ) prototype produced 14 mV at 340 K and a surface temperature differential of 22.5 °C . Performance was further enhanced through Ag incorporation in CuI, yielding both p-type (Ag0.2Cu0.8I, ZT = 0.47) and remarkably high-performance n-type (Ag0.9Cu0.1I, ZT = 2.5) enabling an Ag–CuI TEGZ prototype to deliver 104 mV under a 40 K temperature gradient. Further, Lead-free perovskite (Cu2AgBiI6) exhibited outstanding TE performance, reaching a ZT of 3.49. Cross-plane TEGZ generated up to 182 mV at a 19 K gradient and sustained a 47 K temperature difference between indoor and outdoor. it also demonstrated in wearable TE prototypes harvesting 288 mV from body heat. Finally, in addition to TE, Al/Fe dual-doped ZnO nanorods were also tested for photoelectrochemical hydrogen production, delivering a photocurrent of 3 mA cm-2 at 0.25 V vs Ag/AgCl with stable operation for over 6000 s.<p></p>

Author dc:creator

• Mustafa Al-Fartoos (21053303)

• Thermoelectric
• Thermoelectric Materials
• Thermoelectric Glazing (TEGZ)
• Energy Harvesting
• Semi-Transparent Windows
• Building Energy Efficiency
• Net-Zero Buildings
• Room-Temperature Thermoelectrics
• Aluminium-Doped Zinc Oxide (AZO)
• Copper Iodide (CuI)
• Silver-Doped Copper Iodide
• Lead-Free Perovskites
• Cu₂AgBiI₆ (CABI)
• Transparent Conductive Oxides
• Nanostructured Materials
• Fluorine-Doped Tin Oxide (FTO)
• Seebeck Coefficient
• Figure of Merit (ZT)
• Sustainable Energy Technologies
• Scalable Thin-Film Deposition
• SILAR Deposition
• Electrochemical Deposition
• Drop-Casting
• Thermal Management
• Waste Heat Recovery
• Wearable Thermoelectric Devices
• Photoelectrochemical Hydrogen Production
• Hydrogen Generation
• Renewable Energy Materials
• Nanostructure
• Nanomaterials
• Nanorods
• Thin Film

Statement dc:rights

• All rights reserved
• Open Access after 2027-12-08

Identifier

10779/exe.32603595.v1

OAI identifier oai:identifier

oai:figshare.com:article/32603595