(Invited) Electrocatalysis and Photoelectrochemistry Based on Modified Titanium Dioxide Nanomaterials

Abstract

With an ever-increasing population, the importance of industrial processes to ensuring enough food and energy are produced to meet increasing demand cannot be understated. Unfortunately, these processes often produce byproducts that become waste and cause ecological damage. A large concern arises when these waste products enter the water system, resulting in serious consequences for the environment. Various methods have been explored towards the removal of these pollutants. Catalysis plays a key role in chemical production, energy conversion and storage, air purification, water treatment, food processing, and the life sciences. In this presentation, we report on the preparation and modification of TiO2 nanostructured materials as advanced electrocatalysts and photocatalysts for environmental applications and water disinfection. TiO2 nanopores and nanotubes were directly grown on a titanium substrate using anodization processes. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction were employed to characterize the formed TiO2 nanostructures. The electrocatalytic and photocatalytic activities of the nanoporous and nanotubular TiO2 were investigated by the degradation of phenolic pollutants and lignin, a byproduct of the pulp and paper industry, as the model pollutants. The formed TiO2 nanostructures were further treated using electrochemical methods in enhance their catalytic activities. The effectiveness of electrochemical and photoelectrochemical degradation of phenolic species and lignin was determined by UV-Visible spectroscopy and total organic carbon analyzer. The effect of the growth time, the morphology, and the electrochemical treatment on the performance of the formed nanoporous and nanotubular TiO2 is discussed. In addition, the increasing lack of drinking water around the globe is of great concern. The synergistic effect of the integration of photocatalysis and electrocatalysis on bacterial disinfection is highlighted.