Shockwave impact on the stability of anatase titania nanoparticles

The stability of anatase titania nanoparticles was investigated under exposure to repeated loading of shockwaves produced in a diaphragm-driven high-pressure shock tube. The titania samples were exposed to 20 shocks with pressure, temperature, and steady exposure time in the range of 20.5 – 26 bar, 1399 – 2101 K, and 1.74 – 1.83 ms, respectively. The crystal structure and surface morphology were analyzed before and after the shockwave treatment using various characterization techniques. After repeated shock exposure, there was reduction in crystallite size by ~ 40%, modification in the surface charge, and an increase in the hydroxyl groups in titania. The onset of phase transformation from anatase to rutile was observed after 20 shocks. This work gives insights into the structural changes induced by shockwaves in anatase nanoparticles which can help improve their performance as a catalytic support in heterogeneous catalysis.