TiO2-based Photoelectrocatalysis Technology for Degradation and Detection of Organics in Wastewater

With industrialization rapidly progressing in recent decades, great amounts of refractory organic pollutants are found in water bodies, which severely jeopardizes ecosystem health. Monitoring the organic compounds in water bodies and removing organic pollutants from wastewater is essential for ameliorating threats to aquatic life and human health. Photocatalytic (PC) and photoelectrocatalytic (PEC) degradation and detection of organic pollutants in wastewater are promising strategies for fulfilling these goals sustainably, since PC and PEC technologies can take advantage of solar energy, which is one of the most abundant energy sources on earth. Titanium dioxide (TiO2) is a commonly used photocatalyst due to its appropriate band position, high chemical stability, low cost, and nontoxicity. However, pristine TiO2 photocatalysts can only be stimulated by UV irradiation because the band gap of pristine TiO2 is higher than 3.0 eV, which seriously impedes its development with low-cost and environmentally friendly solar energy. There are several efficient strategies to overcome these disadvantages of pristine TiO2, such as morphology modification, bandgap engineering, and applying co-catalysts with the host photocatalysts. Herein, this thesis aims to utilize different strategies to enhance the photocatalytic performance of TiO2-based photocatalysts under visible light irradiation and apply those modified photocatalysts to degradation and detection of organics in wastewater. In the first study, a photoelectrochemical Chemical Oxygen Demand (COD) sensor based on a linear photocurrent-concentration analytical principle was designed for the on-site determination of COD. A high-performance anatase-branch@hydrogenated rutile-nanorod TiO2 (AB@H-RTNR) photoelectrode was fabricated. The as-prepared photoanodes successfully achieved sensitive determination of COD with a detection limit of 0.2 ppm (S/N = 3), an RSD% of 1.5 %, a wide linear detection range of 1.25−576 ppm, and an ave
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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