Effects of Nd, Fe, Cu doping on crystal structure and photocatalytic properties of TiO2 powders prepared by sol-gel method

In the present work, titanium dioxide (TiO₂) doped with 1 at% of Neodymium (Nd), Iron (Fe), copper (Cu), Nd-Fe and Nd-Cu co-doping and pure TiO₂ powders (800 °C) were prepared by sol-gel method. XRD spectra revealed that the TiO₂ crystalline phase maintains anatase phase after Nd doping, while the introduction of transition metals does not change the original rutile crystalline phase of the pure powders, but the crystalline phases of the rare earths co-doped with the transition metals appeared to have different results. XPS clarifies the chemical state and effects of sample elements. SEM and TEM showed that Nd doping resulted in the refinement of TiO₂ particles, while Fe or Cu doping resulted in significantly larger particles. Simulated visible light degradation of methylene blue showed that doping with Nd elements significantly increased the degradation efficiency, while doping with Fe and Cu had the opposite effect.