Assessment of mechanisms for enhanced performance of Yb/Er/titania photocatalysts for organic degradation: Role of rare earth elements in the titania phase

By Bhethanabotla, Vignesh C.; Russell, Daniel R.; Kuhn, John N.
Published in Applied Catalysis B: Environmental NULL 2017

Abstract

Abstract The effect of doping titania with rare earth erbium and ytterbium ions on photocatalytic degradation of a real pollutant (phenol) and a model pollutant was studied under simulated solar radiation and using light of specific frequencies in the ultraviolet, green, red, and infrared regions via LEDs. The goal of this study was to quantify the effect of these dopants on photocatalytic degradation rates and critically assess the phenomena (upconversion, adsorption, recombination kinetics, etc) responsible for improved performance upon rare earth ion doping of titania. A hydrothermal process was modified to synthesize pure anatase and rare earth ion doped TiO2. The doped catalysts contained 2% Er and 0, 10, 15, or 20% Yb, on an elemental basis. These photocatalysts were characterized for structure, composition, surface area, particle size, bandgap, and band edge positions. The results indicated that the rare earth elements substituted in the titania phases, which were the crystalline anatase and amorphous titania phases. Aqueous-phase photocatalytic degradation rate constants for both organics under a variety of light irradiation conditions were quantified via slurry batch reactor studies in the liquid phase using pseudo first-order kinetics. On reactor volume and catalyst mass bases (same trends due to same catalyst loading), the 2% Er/TiO2 catalyst performed ?3

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