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 (PO2 ) to obtain a loose white product mainly composed of mZnOw. It was found that the PO2 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 PO2 on these characteristics was also
proposed.