Enhanced visible-light-driven photocatalytic performance of AgNbO3 cubes with a high-energy (001) facet

• Published in: The Journal of physics and chemistry of solids 2019-12, Vol.135, p.109083, Article 109083
• Main Authors: Gao, Bifen, Hu, Desheng, Xiao, Caixia, Li, Dongxu, Lin, Bizhou, Chen, Yilin, Zheng, Yun
• Format: Article
• Language: English
• Subjects: Crystal structure; Microstructure; Semiconductors; Surface properties
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2019.109083

AgNbO3 cubes with an exposed high-energy (001) facet were prepared by hydrothermal treatment of Ag2O–Nb2O5–NH4HF2 aqueous suspension. The crystal phase, surface microstructure, and optical properties of the samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and UV–vis diffuse reflectance spectroscopy. The energy band structure and charge carrier separation efficiency were investigated by photoelectrochemical measurements. In comparison with AgNbO3 powder, whose surface was dominated by a low-energy (114) facet, the AgNbO3 cubes had superior visible-light-driven photocatalytic activity for degradation of tetracycline because of the greater redox ability and more efficient separation of photogenerated electrons and holes. The surface F− ions had no influence on the photocatalytic reactions. Radical trapping experiments demonstrated that the superoxide radical played a decisive role in the photodegradation of tetracycline. AgNbO3 cubes, with a high-energy (001) facet, exhibit enhanced visible-light-driven activity for degradation of tetracycline compared with AgNbO3 powder, with a low-energy (114) facet. [Display omitted] •AgNbO3 cubes show excellent visible-light-driven activity for photodegradation of tetracycline.•AgNbO3 cubes exhibit greater redox ability and more efficient separation of charge carriers in comparison with AgNbO3 powder.•Superoxide radicals are the dominant oxidation species in the degradation of tetracycline over AgNbO3 cubes.