Enhanced Photocatalytic Activity of Ag3VO4 Loaded with Rare-Earth Elements under Visible-Light Irradiation

• Published in: Industrial & engineering chemistry research Vol. 48; no. 24; pp. 10771 - 10778
• Main Authors: Xu, Hui, Li, Huaming, Xu, Li, Wu, Chundu, Sun, Guangsong, Xu, Yuanguo, Chu, Jinyu
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 16.12.2009
• Subjects: Applied sciences; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Exact sciences and technology; General and physical chemistry; Kinetics, Catalysis, and Reaction Engineering; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Photocatalysis; Visible radiation
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie900835g

Rare-earth-loaded Ag3VO4 catalysts (RE3+-Ag3VO4, RE = Nd, Sm, and Eu) were prepared by the wetness impregnation technique and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of the samples were evaluated by rhodamine B (RhB) dye degradation under visible-light irradiation. It was found that the presence of rare-earth oxides in the host Ag3VO4 could decrease the band gap and accelerate the separation of photogenerated electron−hole pairs, which led to higher photocatalytic activities. Among the rare-earth-loaded samples, Nd3+-loaded Ag3VO4 catalyst showed the highest photocatalytic activity. The optimum contents of Nd3+, Eu3+, and Sm3+ were found to be 2, 3, and 2 wt %, respectively. It was also found that the photocatalytic degradation of RhB over RE3+-Ag3VO4 (2 wt %) followed pseudo-first-order kinetics. A possible mechanism for RhB photocatalytic degradation over RE3+-Ag3VO4 catalysts is also proposed.