Investigation of structural and textural properties of GexMoO3 system, promising catalyst for photocatalytic applications

Abstract

The main objective of this work is to control the structural, textural and electrical properties of the system prepared by mixing molybdenum oxide with different amounts of germanium. The system is expected to be suitable as a catalyst for the photodegradation of methyl red (one of the dyes group) and the results of this study can throw some light on the relationship between the properties of this system and the extent of the dye degradation as indicated by the measurements of the photocatalytic activity. The composite materials (Ge_xMoO₃) were prepared by solid-state reaction between germanium and molybdenum oxide. The mixtures were made in Ge/MoO₃ molar ratios of 0.01, 0.05, 0.1, 0.2, 0.5, and 1.0. The reaction was conducted in air at 700°C. The prepared samples were characterized by X-ray powder diffraction, micro-Raman spectroscopy, nitrogen adsorption measurements, diffuse reflectance spectrometry and UV-Vis absorption spectrophotometry. The addition of germanium has affected the photocatalytic activity of MoO₃ as evidenced by an increase in the degradation extent of methyl red from about 14% (for pure oxide) to about 97% for Ge_xMoO₃ (x = 1). An enhancement in the photocatalytic activity was attributed to the change in the band gap and modification of the textural properties associated with the formation of Ge_xMoO₃ composites.