- Research Grants
|Support type:||Scholarships in Brazil - Post-Doctorate|
|Effective date (Start):||July 01, 2016|
|Effective date (End):||September 30, 2018|
|Field of knowledge:||Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry|
|Principal Investigator:||Sidney José Lima Ribeiro|
|Home Institution:||Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil|
Heterogeneous photocatalysis based on semiconductor materials, especially TiO2, is an efficient method for environmental clean-up. However, practical applications of semiconductor photocatalysts, beside other factors such as recombination of charge carriers (e--h+ recombination), are limited by the requirement of continuous supply of UV light, which is only around 6% of the solar spectrum. The development of TiO2 based composite photocatalysts responsive towards visible and near infrared (NIR) radiation is thus of immense importance. In this project, attempts will be made to extend the application of TiO2 to visible and IR region of the spectrum by preparing two types of composite photocatalysts with a core@shell configuration: (1) Visible light-driven photocatalysts (VLPC), with an architecture represented as SiO2@WO3@TiO2/Ag and (2) NIR light-driven photocatalysts (IRLPC) represented as UC@TiO2 or UC@WO3 where UC is an upconversion (UC) material like NaYF4:Nd3+:Yb3+, Tm3+. In case of VLPC, the active components (WO3, TiO2 and Ag) will be supported on SiO2 sub-micron particles in a core@shell configuration based on our previously developed methods (Ullah et al. 2015). The composite core@shell photocatalyst is expected to be active under both UV (direct activation) and visible light (indirect activation) illumination and show improved photocatalytic and antibacterial activity due to increased specific surface area, better dispersion and higher thermal stability of the supported TiO2 and efficient absorption/harvesting of light. The IRLPC will be prepared by coupling TiO2 (and/or WO3) with UC materials such a rare earth metal-based crystals (NaYF4:Nd3+:Yb3+, Tm3+). The UV light emitted by the UC component upon absorption of NIR radiation can be used to excite TiO2 coated as thin film on the surface UC particles. The photoactivity of the photocatalysts as function of composition and architecture as well as illumination mode (pulsed illumination/steady illumination) will be evaluated both in presence of UV-visible light (for VLPC) and NIR light (for IRLPC only) as illumination sources. Finally, the composite photocatalyst will be tested for disinfection of water in a homemade photo-reactor under optimized illumination conditions.