Engineered functional films for photo-electro-chemical sensing of environmental matters
Date of Award
Edith Cowan University
Doctor of Philosophy
School of Science
The identification and detection of harmful substances in various matrices has gained significant attention due to the negative impacts they have on human health and aquatic life. To address this issue, various analytical techniques have been developed and utilized by monitoring agencies and regulatory bodies. However, many of these techniques are complex, costly and require specialized equipment and trained personnel to operate. Furthermore, the large and cumbersome nature of these techniques makes it difficult to conduct measurements in the field. Additionally, some of these techniques may not be sensitive enough or selective enough and require time-consuming sample preparation procedures.
Electrochemical (EC) and Photoelectrochemical (PEC) techniques are gaining significant attention in the field of environmental monitoring and clinical analysis due to their sensitivity, cost-effectiveness, simplicity, rapid operation, flexibility, and device miniaturization. The adaptability of electrochemical and photoelectrochemical techniques, combined with the emergence of novel materials and technology, has facilitated the creation of various methodologies for identifying environmental contaminants and clinical pollutants with heightened sensitivity and specificity. To this end, nanocomposites of transition metals and their oxide (Ni, Co, Fe), along with carbonaceous materials (g-C3N4) were redesigned with engineered approaches to improve the efficiency of EC and PEC sensors.
In this thesis, novel strategies for the preparation and modification of these nanocomposites are presented to improve the performance of the EC and PEC technologies. The physical, electronic, and chemical properties of these nanocomposite materials were carefully manipulated and adjusted to produce core shell nanoarrays, layered double hydroxide, and heterostructures morphology for highly promising electroactive and photoactive sensing platform for detecting 4-chlorophenol, nitrite, and glucose. Different synthesis techniques, including electrodeposition, electroreduction, chemical reduction, and template-assisted synthesis were used to attain the desired fine-tuned morphology. Advanced characterization techniques such as SEM, TEM, XRD, XPS, BET, PL, and UV-Vis were then utilized to determine the materials' architectural and structural composition. Subsequently, the use of a binder-free current collector, such as a 3 dimensional (3D) porous metal foam, instead of traditional Indium Tin Oxide (ITO) and Fluorine-doped Tin Oxide (FTO) was systematically explored to make it more attractive option for use in EC and PEC applications. The influence of operation parameters such as solution pH, applied voltage, and catalyst loading was comprehensively investigated and optimized for practical application, highlighting the significance of the work in advancing electrochemical and photoelectrochemical sensing. This study aimed to contribute to the successful implementation of proof-of-concept experiments that utilize nanocomposite materials with rational design and cutting-edge technology in the field of EC and PEC sensing. These developments have the potential to significantly enhance the capabilities and precision of these sensors for the development of more efficient and cost-effective devices in the future.
Access to this thesis has been embargoed until 31st May 2026
Rafique, N. (2023). Engineered functional films for photo-electro-chemical sensing of environmental matters. Edith Cowan University. http://dx.doi.org/10.25958/34y7-z464