Table 4: The size of primary particles (of the “as-received” powders), as defined by their corresponding Feret’s diameter. Mean diameter (±1 SD) of a minimum of 50–100 particles measured in the SEM images; the SD here represents the broadness of the size distribution.

Sample nameSupplierMean Feret diameter (±1 SD) from SEM images

Nanograin CeO2Umicore Belgium28.4 ± 10.4
Nanosun ZnOMicronisers, Australia42.5 ± 3.6
Micron ZnOSigma Aldrich, UK891.8 ± 800.0
Z-COTE ZnOBASF, Germany151.0 ± 55.6
Micron CeO2Sigma Aldrich, UK615.3 ± 430.5
Ceria dry CeO2Antaria, Australia44.9 ± 14.6