Synthesis and characterization of multipod zinc oxide whiskers synthesized via a modified self-propagating high-temperature synthesis method

A self-propagating high-temperature synthesis (SHS) method, which features a 2-step heating process carried out in a closed chamber, was developed to prepare multipod ZnO whiskers (mZnOw). A compacted Zn powder was first heated at 370 °C in air to form a refractory layer of ZnO on the surface of Zn particles. Next, the SHS reaction was ignited by rapidly heating to ∼750 °C under different oxygen gauge pressures (PO2PO2) to obtain a loose white product mainly composed of mZnOw. It was found that the PO2PO2 strongly affected the reaction conversion and morphological features, along with the Zn-to-O ratio, of the as-synthesized products, which, in turn, might influence their photoluminescence and microwave absorption properties. A possible explanation for the effects of PO2PO2 on these characteristics was also proposed.