Hydrothermal and surfactant treatment to enhance the photocatalytic activity of hierarchically meso–macroporous titanias

The photocatalytic activities of various hierarchically meso–macroporous titanias, obtained via a spontaneous self-formation process using titanium isopropoxide, have been investigated by comparing each materials’ capability to photodegrade Rhodamine B. Three synthesis routes have been developed to synthesize hierarchically meso–macroporous titania materials: (A) in water without and (B) with hydrothermal treatment and (C) in a surfactant Brij 56 aqueous solution with hydrothermal treatment, respectively. These results show that the introduction of surfactant Brij 56 and a hydrothermal treatment in the synthesis system greatly improve the crystallinity of the anatase phase in hierarchically meso–macroporous titanias and their thermal stability, resulting in a remarkable enhancement of their photocatalytic activity. Furthermore, the effect of calcination on hierarchically porous structure and their photocatalytic activity has also been investigated in detail. The properties of the products were characterized by XRD, SEM and N2 adsorption-desorption measurements.

Graphical abstractA simple and effective strategy to enhance the stability and photocatalytic performances of hierarchically meso–macroporous titanias via a spontaneous self-formation process using titanium isopropoxide in a surfactant Brij 56 aqueous solution with hydrothermal treatment has been described. The effect of a hydrothermal treatment and the addition of Brij 56 into the reaction system on the resultant hierarchically porosities and their photocatalytic activities have been investigated.Figure optionsDownload full-size imageDownload high-quality image (197 K)Download as PowerPoint slideHighlights► Hierarchically meso–macroporous titanias. ► Spontaneous self-formation process from titanium isopropoxide. ► Thermal stability, crystallinity and photocatalytic activity enhancement. ► Hydrothermal treatment. ► Addition of surfactant molecules Brij 56.