Synthesis and photocatalytic activity of sulfate modified Nd-doped TiO₂ under visible light irradiation

Nd-doped TiO₂ (NT) photocatalysts with different contents of Nd were synthesized by sol-gel method. Then sulfated Nd-doped TiO₂ (SNT) solid superacid photocatalysts were prepared by an incipient wetness impregnation technique. The photocatalytic activity of catalysts was evaluated by the photodegradation of methylene blue under visible light irradiation. Analytical results demonstrated that Nd doping inhibited the growth of TiO₂ crystallite and enhanced the thermal stability of anatase TiO₂. Meanwhile, sulfate ions modification increased the specific surface area of samples. In addition, the optical absorption edges of SNT photocatalysts shifted to longer wavelength compared with the undoped TiO₂. Such SNT with Nd dosage of 0.25 at.% exhibited the highest photocatalytic activity in the degradation of methylene blue upon irradiation with visible light.