Synthesis of novel, visible-light driven S,N-doped NaTaO3 catalysts with high photocatalytic activity

Highly effective S,N-co-doped NaTaO3 catalysts were successfully prepared through a facile polymerized complex technique. The catalysts were analyzed by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Diffuse reflectance spectroscopy (DRS), Energy Dispersive X-ray analysis (EDX), and ultraviolet-visible absorbtion spectroscopy. Based on the XRD results, the structure of as-prepared co-doped NaTaO3 is monoclinical. EDS and XPS results showed that both sulfur and nitrogen were incorporated into the NaTaO3 martrix and occupied O2- sites. The co-doped S and N could create an additional energy level, resulting in narrowed band gap, increased visible light absorption capacity and the upward-shifted valence band edge. The photocatalytic activity evaluation through the visible light degradation of Rhodamine B indicated significantly higher activity of co-doped samples (95% degradation in water after 1 h). The synergistic effect of the monoclinic, porous structure and narrowed band gap may be responsible for an excellent photocatalytic activity.