ABSTRACT
Potassium birnessites were prepared using two methods, sol–gel or oxidation. The solids were characterised by element chemical analysis, powder X-ray diffraction, FT-IR spectroscopy, thermal analyses, and nitrogen adsorption. The evolution of the properties as a function of the preparation method was discussed. The photocatalytic performance of these solids was preliminarily tested for the degradation of 4-nitrophenol. The degradation pathway and the nature of the by-products were investigated by mass spectrometry. The solids showed good catalytic behaviour, although their preparation must be improved, mainly concerning the calcination step involved in sol–gel synthesis, which led to the formation of Mn2O3 that worsened the catalytic behaviour.
GRAPHICAL ABSTRACT
Acknowledgements
BG thanks a pre-doctoral grant from Universidad de Salamanca. AG thanks Santander Bank support through the Research Intensification Program.
Disclosure statement
No potential conflict of interest was reported by the author(s).