Abstract
In recent decades, layered perovskite-like oxides have been intensively investigated as prominent photocatalysts for water splitting as a method of hydrogen production. In many previous papers, it was shown that deposition of platinum on an oxide sample dramatically increases photocatalytic activity. Nevertheless, little research was conducted to reveal the localisation of platinum in layered oxides; either it is located on the surface or in the interlayer space. In the present work, an attempt to answer this question is made. An HCa(2)Nb(3)O(10) layered perovskite-like oxide was modified with platinum by photoreduction of H(2)PtCl(6) and then was intercalated with n-alkylamines (R = Me, Bu, Oc). Moreover, another set of samples were prepared by intercalating the amines first into HCa(2)Nb(3)O(10), followed by Pt deposition. Besides conventional methods for sample characterisation, we measured the kinetics of Pt dissolution during aqua regia etching of the samples, hoping that the rate of platinum dissolution would provide some information about its localisation. It was shown that in HCa(2)Nb(3)O(10) modified with platinum, less than 20% of the platinum is located on the surface, and that in the case of HCa(2)Nb(3)O(10) intercalated with amines, an even smaller amount of platinum attaches to the surface. Moreover, Pt in HCa(2)Nb(3)O(10) intercalated with amines was found to be significantly more stable against aqua regia treatment than in HCa(2)Nb(3)O(10) decorated with platinum directly.