The pH dependent surface charging and points of zero charge. VI. Update.

The pristine points of zero charge (PZC) and isoelectric points (IEP) of metal oxides from the recent literature are summarized. This study is an update of the previous compilation (Kosmulski, 2009) and of its previous updates (Kosmulski, 2009, 2011). Only the IEP of materials other than metal oxides are reported, and the PZC of such materials obtained by potentiometric titration and related methods are ignored. IEP of (nominally) CoO, Fe(OH)2, Gd2O3, Ni2O3, and Sb2O3 have been reported in the recent literature. Those materials have not been studied before.