Chemistry Masters Candidate Thesis Defense Presentation
Emmanuel Albert Mensah, Candidate
Dr. Zhihai Li (Advisor)
"Synthesis of Metal Oxide Nanomaterials for the Photodegradation of Environmental Pollutants and Organic Molecules"
Tuesday, June 2nd, 10am
Foundational Science Building - FB-253
Abstract: This work focused on the synthesis and characterization of Ag-NiWO4 nanomaterials with varying silver concentrations for photocatalytic applications. Co-precipitation was used to create crystalline cocatalyst nanomaterials (0%, 3%, 6%, and 9% Ag-NiWO4) and hollow spherical structures (0%, 3%, and 6% Ag-NiWO4). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive spectroscopy (SEM–EDS), transmission electron microscopy (TEM), and UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS) were used to evaluate the produced materials. While SEM and TEM data showed nanoscale morphologies with particle sizes about 50 nm, XRD analysis verified the successful formation of NiWO4 structures with Ag inclusion. Ag loading improved visible-light absorption and changed the band gap properties, according to optical experiments. The Ag-modified materials showed enhanced photocatalytic performance among the produced samples due to increased charge separation and decreased electron–hole recombination. In addition, preliminary studies on WO3 afterglow photocatalysis indicated promising charge storage behavior for future environmental applications. These findings demonstrate that morphology control and Ag incorporation significantly improve the properties of NiWO4-based photocatalysts for pollutant degradation and energy-related applications.