Preparation and photocatalytic degradation of erbium doped titanium dioxide nanorods

摘要

Photocatalytic degradation of methylene blue (MB) in water was examined using Er ~3-doped TiO _2 (Er-TiO _2) nanorods prepared by a sol-gel derived electrospinning, calcination, and subsequent mechanical grinding. Different concentrations of Er dopant in the range of 0-1.0 mol% were synthesized to evaluate the effect of Er content on the photocatalytic activity of TiO _2. Among Er ~3-TiO _2 catalysts, the 0.7 mol% Er ~3-TiO _2 catalyst showed the highest MB degradation rate. The degradation kinetic constant (k) increased from 1.0 × 10 ~(-3) min ~(-1) to 5.1 × 10 ~(-3) min ~(-1) with the increase of Er ~3 doping from 0 to 0.7 mol%, but decreased down to 2.1 × 10 ~(-3) min ~(-1) when Er ~3 content was 1.0 mol%. It can be concluded that the degradation of MB under UV radiation was more efficient with Er ~3-TiO _2 catalyst than with pure TiO _2. The higher activity might be attributed to the transition of 4f electrons of Er ~3 and red shifts of the optical absorption edge of TiO _2 by erbium ion doping.