Preparation of MoO₃ powder by hydrothermal method

Abstract Based on the raw material of ammonium tetramolybdate in the experiment, molybdenum trioxide was prepared by hydrothermal synthesis, and the effects of different pH, hydrothermal reaction time, filling degree, and calcination temperature on molybdenum trioxide powder were studied. Meanwhile, the molybdenum trioxide powder was characterized through scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and thermal analysis differential scanning calorimetry analysis so as to study the morphology and phase changes during the experiment. As is evident from the research findings, MoO3 powders with uniform and suitable size, smooth and clear surface, good dispersibility, and no adhesion can be obtained at the conditions of pH = 1, 16 h hydrothermal reaction, 90% of filling degree, and 550°C of calcination temperature. In the calcination process, MoO3 crystal undergone crystal transformation and was completely transformed from h-MoO3 to α-MoO3 at the calcination temperature of 350°C.