Direct obtaining of pure anatase TiO2 nanostructures, characterization, size-tuning, and applications

Research on nanoparticles and their applications in pollutant elimination and transformation has proven to be a practical approach to dealing with these environmental problems. However, effectively tuning the nanoparticle size and shape is still challenging. This article mainly focused on the synthetic approach for pure anatase TiO2 systems, their characterization, size tuning optimization, and their application in dye photodegradation and as support of WS2 nanoslabs. The synthesis parametric analysis allowed us to obtain nanoparticles from 6.5 μm to 15 nm via the hydrothermal method assisted by urea. The mechanism of nanoparticles formation is discussed in light of the surfactant (TX-100) and urea effects observed. Urea in high concentrations allows the formation of hexagonal and cuboctahedron-shaped nanocrystals of around ∼20 nm that function as a seed for large spherical microparticles. XRD results confirmed the presence of high intensity (101) family planes of anatase. Also, the XPS results revealed that the Ti 2p signal does not shift due to the particle size effects. However, raising urea quantities in the synthesis procedure increases the adsorbed carbon species at the surface of nanoparticles. This effect was also observed in the photocatalytic degradation of red amaranth dye. The smallest titania nanoparticles were used as support for WS2 nano slabs, demonstrating that it would be possible to generate sulfide fullerene-like structures at the surface. These curved nanoparticles allowed dislocations on the WS2 nano slabs to form new active sites at typically hydrodesulfurization inactive basal planes. [Display omitted] •TiO2 anatase particle size was successfully modulated from micro to nanoscale.•XPS results revealed that binding energies of Ti 2p are not particle size-dependent.•TiO2 nanoparticles showed encouraging results in the photodegradation of red amaranth dye.•Spherical nanoparticles were used as support of WS2 generating curvature to the normally flat slabs.