Author Identifier

Seyedehzahra Haeri: http://orcid.org/0000-0003-0596-6309

Date of Award

2025

Document Type

Thesis

Publisher

Edith Cowan University

Degree Name

Doctor of Philosophy

School

School of Engineering

First Supervisor

Masoumeh Zargar

Second Supervisor

Mehdi Khiadani

Third Supervisor

Bahram Ramzanzadeh

Abstract

Global energy demand continues to grow, making the reliance on fossil fuels increasingly unsustainable due to dwindling reserves and environmental impacts. Among these, solar thermal systems have emerged as a practical and environmentally friendly solution, with applications ranging from industrial heating and solar water heating to concentrated solar power (CSP) plants and solar desalination units. Solar-based thermal systems offer a promising alternative, with nanofluids (NFs) emerging as a transformative solution. Engineered by dispersing nanoparticles into base fluids, NFs enhance thermal conductivity, heat absorption, and efficiency. Notably, nanoparticles such as titanium nitride also act as nano-catalysts, improving chemical reactions and reducing waste in solar-driven processes like hydrogen production and photocatalysis. NFs significantly boost the performance of solar collectors, concentrated solar power plants, and desalination systems, representing a critical step towards cleaner, more sustainable energy solutions.

Metal-Organic Frameworks (MOFs), a class of highly porous materials, are gaining recognition for their exceptional energy adsorption, storage, and transfer properties. MOFs have been extensively studied for solar energy harvesting due to their ability to absorb specific wavelengths of light, making them ideal for applications such as solar thermal storage systems and photocatalysis. With tunable porosity and surface chemistry, MOFs enhance light absorption, thermal stability, and energy conversion efficiency, providing a cutting-edge pathway for solar energy utilization.

The performance of MOF-based NFs can be further improved by incorporating advanced nanoparticles such as Titanium nitride (TiN) and MXenes. Titanium nitride nanoparticles are particularly promising due to their superior photothermal conversion efficiency, high thermal stability, and unique plasmonic properties, which significantly enhance the heat absorption, energy conversion, and thermal conductivity of MOF-based NFs. Similarly, MXenes, with their layered structure, high electrical conductivity, and outstanding thermal characteristics, synergize effectively with MOFs to optimize solar energy capture and transfer. The integration of TiN and MXenes into MOF-based NFs creates hybrid materials with enhanced solar absorption, improved energy storage, and superior heat transfer properties.

This thesis introduces innovative strategies for incorporating advanced nanocomposites into base fluids such as water and ethylene glycol, aiming to improve their optical properties, stability, and photothermal performance for solar energy harvesting. These nanofluids not only facilitate more efficient solar-to-thermal energy conversion but also reduce heat losses and improve overall system efficiency, even at lower nanoparticle concentrations. By integrating novel nanocomposites into solar thermal systems, this study aims to support the development of cost-effective, scalable, and high-performance renewable energy technologies, thereby contributing to the broader transition toward sustainable and low-carbon energy solutions. A range of nanoparticles and nanocomposites, including NH2-MIL125 (Ti), titanium nitride, NH2-UiO-66 (Zr), TiN/NH2-MIL125 (Ti), MIL-88B (Fe), MXene/NH2-UiO-66 (Zr), MXene/MIL-88B (Fe), and MXene/NH2-MIL125 (Ti), were synthesized and characterized using advanced techniques. These included X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDXS), and Brunauer-Emmett-Teller (BET) analysis. The synthesized materials were incorporated into base fluids, and their photothermal and stability properties were evaluated using a range of parameters, including thermal conductivity, transmittance variations, zeta potential, spectral irradiance, solar energy absorption fraction, temperature distribution, surface and bulk temperature profiles, and photothermal conversion efficiency. This research offers valuable insights into the development of advanced hybrid NFs, making a significant step forward in improving the efficiency and adaptability of solar energy systems. By integrating novel materials and employing advanced characterization techniques, this work establishes a strong foundation for future innovations in sustainable energy harvesting.

Comments

Author also known as Zahra Haeri

DOI

10.25958/6sgr-ys10

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