Synthesis and Characterization of Nanocomposites-based Materials for Electrochemical Sensing Applications
About this ebook
This thesis focuses on the synthesis of different morphologies and characterization of some metal oxides (ZnO, α-Fe2O3 and Au nanoparticles (NPs)), well suitable for electrochemical sensors applications. This thesis is divided into two parts:
In the first part of this research work, the fabrication of α-Fe2O3 nanorods (NRs) and nanoparticles (NPs) using different techniques to further develop nanocomposites is presented. The α-Fe2O3 NRs were synthesized using different concentrations of urea using the hydrothermal method. Then, ZnO NRs were composited onto the α-Fe2O3 NRs surface forming a nano-heterojunction. This composite optical properties and electrical conductivity is investigated and presented in paper I.
The α-Fe2O3 NPs were synthesized in different precursor concentrations by the dip coating techniques. The deposition of the α-Fe2O3 NPs onto the ZnO NRs surface samples, were then characterized by cyclic voltammetry for arsenic detection in various solutions and is presented in paper II.
The development of screen-printed electrode for electrochemical sensors by drop casting of ZnO NPs and α-Fe2O3 NPs samples was demonstrated. The samples were characterized by linear sweep voltammetry method for arsenic (V) detection and are presented in paper III.
In the second part of the thesis, Au NPs were deposited onto the ZnO/α-Fe2O3 nanocomposite surface and were utilized to develop an electrochemical sensor. The ZnO/α-Fe2O3/Au NPs samples were characterized by linear sweep voltammetry techniques and were presented in paper IV.
As a summary, the development of nano sensors devices that possess high sensitivity, low limit of detection and have relatively fast response time were demonstrated. The developed sensors were tested for detecting Arsenic in drinking water. The results indicated that the developed sensor properties are acceptable when comparing the performance to the world health organization (WHO) regarding the lower allowed limit of Arsenic in drinking water.
