Hydrothermal synthesis of Nd3+-doped heterojunction ms/tz-BiVO4 and its enhanced photocatalytic performance

摘要

BiVO4 photocatalysts with different Nd3+ doping content were prepared by a hydrothermal method with varied hydrothermal reaction time. The effects of Nd3+ doping on phase transformation, morphology, chemical valence, optical properties and photocatalytic activities were investigated. With different reaction time, phase transformation from tetragonal zircon (tz-BiVO4) to monoclinic scheelite (ms-BiVO4) could be found, and Nd3+ doping played a suppressive role in this process. Scanning electron microscopy showed the morphology evolved from irregular structure to rod-like shapes with phase transformation. The photoluminescence induced by Nd3+ doping could be confirmed by UV-vis diffuse reflectance spectra. Photocatalytic performance tests had been performed under simulated solar conditions and sample with 1 at% Nd3+ doping and 5 h reaction time showed the best performance (89% degradation rate in 90 min). The pH also showed great influence on morphology and phase transformation of samples. Finally, the phyotocatalytic mechanism and effects of Nd3+ in phase transformation were discussed.