The Assembly of TiO2 Nanoparticles into Micrometer-Sized Structures, Photocatalytically Active Under UV and Vis Light

Micrometer‐sized structures consisting of TiO2 nanoparticles were prepared using the sol–gel technique in combination with the structure‐directing agent triethanolamine (TEA). The interaction of the TEA with the hydrolyzed sol–gel products led to the formation of TEA titanate complexes, which then enabled the assembly of sol–gel‐precipitated nanosized powders. A subsequent thermal treatment of these powders resulted in the formation of micrometer‐sized structures consisting of TiO2 anatase and rutile nanoparticles. To characterize the prepared powders, FTIR spectroscopy, XRD analysis, the Brunauer‐Emmett‐Teller method (sBET), UV–Vis spectrometry and electron microscopy (FE‐SEM, and TEM) were employed. The photocatalytic degradation of the azo dye known as methylene blue was monitored under UV and Vis irradiation and showed that the micrometer‐sized structures consisting of TiO2 nanoparticles exhibited a similar photocatalytic activity to submicrometer‐sized structures consisting of TiO2 nanoparticles prepared without TEA.