Intensification of ultrasound-assisted process for the preparation of spindle-shape sodium zinc molybdate nanoparticles

• Sodium zinc molybdate nanopigment synthesis by ultrasound assisted method.
• Effect of cavitation parameters on particle size of SZM nanoparticles is reported.
• Temperature (vapour pressure) has significant effect on the particle size.
• Study of kinetic behaviour during preparation of SZM nanoparticles is reported.

In the present work, sodium zinc molybdate (SZM) nanoparticles were prepared using conventional and an innovative ultrasound assisted co-precipitation of sodium molybdate, zinc oxide and HNO3 at different temperatures. Prepared product was characterized by XRD, TEM, FT-IR, particle size distribution (PSD), TGA and DTA techniques. TEM analysis shows the spindle-shaped morphology of the formed SZM nanoparticles. The average particle size of SZM nanoparticles is found to be lower in case of sonochemical method (78.3 nm) compared to conventional method (340.2 nm) which is attributed to faster solute transfer rate due to ultrasonic irradiation leading to rapid nucleation and restricted growth of SZM nanoparticles. Further, the kinetics of synthesis of SZM nanoparticles are studied using the sonochemical method at different operating temperature and conventional method at 80 °C. It is shown that the rate of reaction is significantly faster at 40 °C compared to other temperatures and also conventional method. This can be attributed to intense cavity collapse at lower temperature (low vapour pressure) compared to higher temperature (high vapour pressure) of the reaction mixture.