Aqueous Crystallization Strategy for Metastable h-MoO3 Crystals with Polyvinylpyrrolidone Induction

• Published in: European journal of inorganic chemistry 2014-07, Vol.2014 (21), p.3322-3329
• Main Authors: Guo, Jingnan, Zhao, Yan, Zhao, Jingzhe, Wu, Jiajing, Song, Yuehong, Tan, Yixin, Wang, Fangping, Hao, Xinli, Lu, Yan, Bao, Fengxia
• Format: Article
• Language: English
• Subjects: Crystal growth; Metastable compounds; Molybdenum; Photochromism
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201402110

Micro‐sized hexagonal‐phase MoO3 (h‐MoO3) crystals were successfully prepared by a polyvinylpyrrolidone (PVP) induced aqueous route with (NH4)6Mo7O24·4H2O and HCl as raw materials. The linear structure of the PVP molecules matches the tunnel structure of the metastable h‐MoO3 crystals and, thus, enables the induced crystallization in an aqueous solution even at near‐ambient temperatures (40–50 °C). The achieved h‐MoO3 crystals have good monodispersity with a one‐dimensional (1D) outline and hexagonal cross‐section. The H+/Mo ratio is another key factor for the synthesis of h‐MoO3 crystals. The photochromic properties of PVP‐dependent samples of h‐MoO3 crystals were studied under natural sunlight irradiation. Hexagonal MoO3 (h‐MoO3) crystals are successfully prepared from (NH4)6Mo7O24·4H2O and HCl by a polyvinylpyrrolidone (PVP) induced aqueous route. The linear PVP molecules match the tunnel structure of metastable h‐MoO3 crystals and enable crystallization in an aqueous solution at near‐ambient temperatures. The photochromic properties of PVP‐dependent samples of h‐MoO3 crystals are studied.