The effect of La on structure, morphology and photocatalytic performance of tantalum oxynitride

Photocatalytic degradation is an effective method to deal with environmental pollutants. TaON has emerged as a potential alternative to conventional photocatalysts and has shown excellent performance. In the study, we doped varying amounts (atomic percentages) of La from 1.0 to 5.0% to enhance the photocatalytic performance of TaON. Characterization by several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Meanwhile, the catalytic performance of TaON photocatalysts doped with different La amounts was investigated using methylene blue (MB) as the simulated pollutant. The results showed that after the doping of La 3+ , TaON was still monoclinic titanite crystal type, but its particle size had been reduced and the particle agglomeration phenomenon had been weakened. Meanwhile, the formed defects and impurity energy levels were favorable to enhance the light absorption ability of TaON and promote the effective separation of photogenerated electrons and holes, thus improving its photocatalytic activity. When the doping amount of La 3+ was 2.0%, the photocatalytic performance of the sample was the best, and the degradation rate could reach 80.7% within 120 min.