Abstract
Molybdenum trioxide (MoO3) micro-belts were successfully synthesized via the sol-gel coprecipitation method. The synthesized material was, then, doped with different concentrations of yttrium element, Y. The influence of the doping concertation on crystallographic, microstructural, optical, and photocatalytic properties has been studied. Good thermal stability has been revealed by thermogravimetric analysis. The X-ray diffraction analysis identified the orthorhombic phase. The peaks were shifted toward the lower 2 theta angle position after doping, confirming the Y3+ substitution in the MoO3 crystal structure. Scanning electron microscope measurements revealed a belt-like shape with a decreasing size when increasing the Y3+ ions concentration. SEM clearly showed a non-homogeneous distribution of second-phase particles, depending on the concentration of yttrium doping, which could be attributed to the Y2Mo4O15 secondary phase. The band-gap energy was shifted to the lower-energies of an amount of 0.61 eV when going from 0 to 10% of yttrium. The photocatalytic performances were monitored through photodegradation of methylene blue under different radiations. It was observed that Y-dopant significantly improved the photocatalytic activity of MoO3, the longer the wavelength the better the removal efficiency. This enhancement could be associated with the doping-induced modification of the band-gap or to the microstructure evolution.