Visible Light Active Ce-doped TiO2 Nanoparticles for Photocatalytic Degradation of Methylene Blue

Background: TiO2 photocatalysts are well-known for variety of applications in a range of important technological areas. The main drawback associated with TiO2 photocatalysts is the use of these particles in presence of UV light for practical applications and hence these particles utilizes very less part of sunlight. The purpose of this work is to introduce new energy levels between the conduction band and valence band, which results in reduction of the band gap. This permits TiO2 to be active under visible light irradiation and increases the degradation activity in sunlight. Methods: This research contain the preparation of Ce-TiO2 NPs through wet dispersion followed by impregnation method and activity study of these catalysts for degradation of methylene blue under direct sunlight. Results: Physicochemical characterization of Ce-TiO2 NPs has been studied by using different techniques such as XRD, IR, UV, SEM, and EDAX. XRD reveals the nanocrystalline nature of all the samples with anatase and rutile phase. The crystallite size of all samples was found in the range of 21-24 nm. UV-Visible absorption measurement revealed that the optical band gap of the doped samples decrease with increase in dopant concentration from 1.0 - 5.0 mol%. The photocatalytic activities of bare/doped TiO2 samples were demonstrated for the degradation of methylene blue (MB) dye under direct sunlight irradiation. Enhanced activity for photocatalytic degradation of methylene blue is shown by doped TiO2 samples as compare to bared TiO2. As dopant content increases, the photocatalytic activity of doped TiO2 NPs also increases due to the lower optical band gap energy than its bare form. Conclusion: In summary, prepared Ce-TiO2 found to be nanocrystalline and visible light active. These prepared catalysts has shown better activity for photocatalytic degradation of methylene blue under sunlight than bared TiO2.