Synthesis of h‐ and <i>α</i>‐MoO₃ by Refluxing and Calcination Combination: Phase and Morphology Transformation, Photocatalysis, and Photosensitization

Abstract

Hexagonal molybdenum oxide (h‐MoO 3 ) nano‐ and microrods were successfully synthesized by refluxing of (NH 4 ) 6 Mo 7 O 24 ·4H 2 O solutions with the pH 1 at 90°C for 1, 3, 5, and 7 h and were further transformed into orthorhombic molybdenum oxide ( α ‐MoO 3 ) microplates by calcination at 450°C for 6 h. These selected products were used to determine the degradation of methylene blue dye under 35 W xenon lamp for 0–180 min, due to the photocatalysis and photosensitization processes. In this research, catalytic activity of the metastable h‐MoO 3 has higher efficiency than that of the thermodynamically stable α ‐MoO 3 . Their phase and morphology transformation was also explained according to the experimental results.