Mg-doped TiO2 nanorods-SrTiO3 heterojunction composites for efficient visible-light photocatalytic degradation of basic yellow 28

Abstract

n this study, a series of Mg-doped TiO2/SrTiO3 heterojunctions were constructed using SrTiO3 nanoparticles anchored onto the surface of TiO2 nanorod arrays. Titanium dioxide (TiO2) nanorods and SrTiO3 nanoparticles were synthesized using the liquid phase deposition (LPD) and sol-gel methods, respectively. The photocatalytic activity of obtained photocatalysts was investigated towards the degradation of basic yellow 28 (BY28) dye under visible-light irradiation compared to the pristine TiO2 nanorods and SrTiO3 nanoparticles. The obtained samples were carefully characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX), X-ray photo- electron (XPS), UV–Vis, and photoluminescence spectroscopy. 1.5 Mg–TiO2/SrTiO3 nanocomposite demon- strated the highest photocatalytic activity and the corresponding apparent rate constants of 0.0255 min which is that is 2.9, 9.4, and 2.3 times higher than TiO2 nanorods, SrTiO3 nanoparticles, and TiO2/SrTiO3 nano- composite, respectively. This enhanced photocatalytic performance can be attributed to the improved charge transfer, more effective electron-hole separation, and a red-shift in light absorption derived from the Mg doping and coupling effect of TiO2 nanorods and SrTiO3 nanoparticles