Surfactant-Free Synthesis of Three-Dimensional Perovskite Titania-Based Micron-Scale Motifs Used as Catalytic Supports for the Methanol Oxidation Reaction

Abstract

We synthesized and subsequently rationalized the formation of a series of 3D hierarchical metal oxide spherical motifs. Specifically, we varied the chemical composition within a family of ATiO3 (wherein “A” = Ca, Sr, and Ba) perovskites, using a two-step, surfactant-free synthesis procedure to generate structures with average diameters of ~3 microns. In terms of demonstrating the practicality of these perovskite materials, we have explored their use as supports for the methanol oxidation reaction (MOR) as a function of their size, morphology, and chemical composition. The MOR activity of our target systems was found to increase with decreasing ionic radius of the “A” site cation, in order of Pt/CaTiO3 (CTO) > Pt/SrTiO3 (STO) > Pt/BaTiO3 (BTO). With respect to morphology, we observed an MOR enhancement of our 3D spherical motifs, as compared with either ultra-small or cubic control samples. Moreover, the Pt/CTO sample yielded not only improved mass and specific activity values but also a greater stability and durability, as compared with both commercial TiO2 nanoparticle standards and precursor TiO2 templates.

Biosynthesis of Peptide Hydrogel–Titania Nanoparticle Composites with Antibacterial Properties

“…Diffraction peaks can also be observed in the scattering profiles of the composites (Figure 3B). While the intense peak at 17.8 nm −1 and the following one at 19.3 nm −1 are also found in the scattering pattern of the TiO 2 NP powder and are consistent with those expected for the anatase crystalline phase [42], additional peaks are observed for q < 17.8 nm −1 in the composites with the highest TiO 2 content. These signals (peaks at q values 2.65, 3.63, 4.53, 6.21, 7.32, 14.64 nm −1 ) suggest the presence of mesoscale ordered structures (lamellar, hexagonal phases) with characteristic spacings of the order of 2 nm, which cannot be found in dry TiO 2 powder but form in the composite hydrogel preparations.…”

Effect of Sodium Laureth Sulfate on Contact Angles of High-Impact Polystyrene and Acrylonitrile–Butadiene–Styrene from Recycled Refrigeration Equipment

“…The appearance of this peak indicates that it is an amorphous material [29]. In the tested sample, there was an additive in the form of titanium oxide (peaks 27.36 ), which is used in dyes applied in polymers [29][30][31][32][33]. Figure 11 presents the XRD spectrum of plastic PS.…”

Surfactant-free synthesis of metal and metal oxide nanomaterials: a perspective

“…4); the designed ATiO 3 micron-scale spheres could be applied as catalytic supports for the methanol oxidation reactions. 77 A hydrothermal technique was also reported for the synthesis of cupric oxide (CuO) spheres and manganese dioxide (MnO 2 ) nanorods to detect glucose as sensors with a high sensitivity of 2360.81 μA mM −1 cm −2 . 78 Accordingly, CuO spheres were prepared on an indium tin oxide (ITO)/glass substrate with no need of surfactants.…”