Thesis (M.Sc.) - Cairo University - National Institute of Laser Enhanced Science - Department of Laser Application in Environmental Metrology, Photochemistry , Photobiology and Agriculture

The oxidation of methanol to formaldehyde is one of the most important industrial reactions nowadays. The conversion of methanol to formaldehyde typically takes place on the surface of a heterogeneous catalyst and the reaction can be catalyzed by the thermochemical or photochemical driving force.Titania-based photocatalysts have attracted immense attention in the scientific community for being a low-cost and robust catalyst material, widely employed for many applications those related to photocatalytic oxidation/reduction processes and light energy conversion. However, titania is characterized by a wide optical band gap (~ 3.2 eV for anatase and 3.0 eV for rutile) which limits its light-harvesting properties to the ultraviolet (UV) region of the electromagnetic spectrum which in turn constitute a small fraction of only about 5% of the solar spectrum energy.Therefore, the physicochemical and optical properties of titania must be modified in order to enhance its absorption characteristics toward a light in the visible range and hence increase its energy conversion and photocatalytic efficiencies. This can enable the utilization of abundant visible light from the natural solar energy spectrum for sustainable energy conversion. Consequently, the improved photocatalytic activity will be reflected on the efficacy of the conversion of the light energy into chemical energy and can lead to enhanced oxidation rates, for example, enhanced photooxidation rates during the photocatalytic oxidation of methanol to formaldehyde

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