Synthesis of hierarchically porous TiO2 nanomaterials using alginate as soft templates

• Synthesis of hierarchically porous TiO2 nanomaterials using alginate as templates.
• TiO2 nanomaterials are composed of TiO2 nanoparticles with the size of about 20 nm.
• Alginate mainly controls the morphology of TiO2 hierarchically porous structures.
• TiO2 nanomaterials exhibited higher photocatalytic activity than commercial TiO2.

We herein report a large-scale synthesis of hierarchically porous TiO2 structures composed of nanoparticles by a facile soft-template method. The natural and abundant biopolymer named alginate acted as sacrificial templates, providing porous structures and controlling the morphology of TiO2 nanoparticles. The size of the resultant TiO2 nanoparticles was around 20 nm. The TiO2 structures were obtained by directly crosslinking Ti4+ ions to alginate and then burning off the biopolymer templates. Based on the observation of various reactive conditions, we propose that the alginate has two important function in the formation of hierarchically porous TiO2 structures. One is acting as a template for the nucleation of TiO2. The other one is to facilitate the formation of porous TiO2 nanomaterials. The photocatalytic property of hierarchically porous TiO2 in UV-light-driven degradation of organic dyes was proved to be better than that of commercial available TiO2.

Figure optionsDownload as PowerPoint slideHierarchically porous TiO2 nanomaterials are produced by binding Ti4+ ions to alginate directly and their structure is controlled by varying the concentration of alginate solution.