Photocatalytic oxidation of water and air contaminants with metal doped BiTaO4 irradiated with visible light

Various metal ions (Al, Nd, La, Ga, Ba, Sn, W, Fe, Co, Cr, Ce, Cu, Sb, Pb, Ni, Ag) doped and undoped triclinic BiTaO4 photocatalysts were synthesized using a solution method. The prepared materials were characterized with high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and UV–vis diffuse reflectance spectroscopy. BiTaO4 doped with various metal ions were tested for photocatalytic oxidation of water and air contaminants with both UV and visible light irradiation. Metal ion doping changed the photophysical properties, but did not alter the crystalline structure of BiTaO4. Enhanced photocatalytic oxidation of toluene in air was observed for dopants such as Al, Nd, La, Ga, Ba, Sn, W, Fe, Sb, Ag, while other metal ions like Cu, Ce, Co, Pb, and Ni induced a detrimental effect on the photocatalytic performance. BiTaO4 doped with La, Ga and Nd catalysts showed much better and stable performance than TiO2 in gaseous toluene oxidation with both UV and visible light. Some metal ion doped BiTaO4 catalysts also have shown good performance in methylene blue degradation in water.