La doped TiO2 nanoparticles for photocatalysis: Synthesis, activity in terms of degradation of Methylene Blue dye and regeneration of used nanoparticles

Abstract

Abstract In this study, bare and Lanthanum (La) doped TiO2 photocatalysts Ti1 − xLaxO2 (x = 0.00-0.025) were prepared by employing a solution-combustion procedure. In this citric acid was utilised as fuel and as a complexing agent. The prepared photocatalysts were characterized by FTIR for the identification of various functional groups, FE-SEM to identify the morphology of nanoparticles, XRD to determine their crystal structure and crystallite size, and DRS to calculate the band gap. Photo-catalytic breakdown of Methylene blue (MB) dye in its aqueous solutions of different concentrations (10, 20, 30, 40 and 50 ppm) was used to examine the activity of synthesized nanoparticles in a UV photochemical reactor (UV-PCR). The dye degradation was found to be first order. The best activity was shown by 1.5% La-doped TiO2 photocatalyst and it was better than the commercial Aeroxide P-25 photocatalyst. The Ti0.985La0.015O2 catalyst could be regenerated and reused up to five times with a minor loss in degradation efficiency of MB dye (30 ppm) about 7.85% at the end of fifth cycle.