On an adsorption/photocatalytic performance of nanotubular Mg$_3$Si$_2$O$_5$(OH)$_4$/TiO$_2$ composite

Here, we study a performance of nanotubular Mg$_3$Si$_2$O$_5$(OH)$_4$/TiO$_2$ hybrid adsorbent/photocatalyst in the process of decolorizing an aqueous solution of crystal violet. The composite material was produced by hydrothermal treatment with one or more subsequent cycles of TiCl$_4$ treatment and vapor-phase hydrolysis according to the molecular layering technique. Decolorization was observed in situ by UV-VIS spectroscopy. It was found that TiO$_2$ deposition yields 2 to 3 times improvement of decolorization performance. Depending on TiO$_2$ phase type - amorphous or crystalline - this rise is related with either enhancement of adsorption rate either appearance of photocatalytic activity. Finally, fitting procedure issues in case of complex decolorization process were discussed.