Microwave Synthesis and Photocatalytic Activity of Nano Lanthanide (Ce, Pr, and Nd) Orthovanadates

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• 作者：Sudarshan Mahapatra ; Susanta K. Nayak ; Giridhar Madras ; T. N. Guru Row
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2008
• 出版时间：September 3, 2008
• 年：2008
• 卷：47
• 期：17
• 页码：6509-6516
• 全文大小：452K
• 年卷期：v.47,no.17(September 3, 2008)
• ISSN：1520-5045

文摘

Lanthanide orthovanadates, CeVO₄, PrVO₄, and NdVO₄, of nanodimensions were synthesized under microwave exposure, and the photocatalytic activities of these compounds were investigated. These compounds exhibit a tetragonal zircon structure, crystallizing in the space group I4₁/amd with a = 7.3733(4) and c = 6.4909(4) Å with Z = 4. The crystal structure was analyzed by powder X-ray diffraction, and the band gap was analyzed by UV−visible spectroscopy. Particle sizes were in the range of 25−30 nm, as observed by transmission electron microscopy. While the energy dispersive X-ray analysis indicates the formation of LnVO₄, thermal analysis of these solids shows stability of the phase up to 1000 °C. The photocatalytic activity of all these orthovanadates has been investigated by degrading various dyes like methylene blue (MB), Orange G (OG), Rhodamine B (RB), Rhodamine Blue (RBL), and Remazol brilliant blue (RBBR) under UV irradiation. Further, these compounds were also used to degrade organic pollutants like phenol, 2,4-dinitrophenol and 2,4-dichlorophenol. The degradation rates of dyes and organics in presence of microwave-synthesized orthovanadates are higher compared to that observed with orthovanadates synthesized by the solid state technique. The microwave-synthesized orthovandates also show chloro-specificity, with the rate of degradation of 2,4-dichlorophenol significantly higher than that observed in presence of Degussa P-25 titania.