Mixed TiO2 Nanoparticles Research Articles

Nanoparticulate TiO2-promoted PtRu/C catalyst for methanol oxidation

To improve the electrocatalytic properties of PtRu/C in methanol electrooxidation, nanoparticulate TiO2-promoted PtRu/C catalysts were prepared by directly mixing TiO2 nanoparticles with PtRu/C. Using cyclic voltammetry, it was found that the addition of 10 wt% TiO2 nanoparticles can effectively improve the electrocatalytic activity and stability of the catalyst during methanol electrooxidation. The value of the apparent activation energy (E a) for TiO2-PtRu/C was lower than that for pure PtRu/C at a potential range from 0.45 to 0.60 V. A synergistic effect between PtRu and TiO2 nanoparticles is likely to facilitate the removal of CO-like intermediates from the surface of PtRu catalyst and reduce the poisoning of the PtRu catalysts during methanol electrooxidation. Therefore, we conclude that the direct introduction of TiO2 nanoparticles into PtRu/C catalysts offers an improved facile method to enhance the electrocatalytic performance of PtRu/C catalyst in methanol electrooxidation.

TiO2 nanoparticles modified polydimethylsiloxane with fast response time and increased dielectric constant

Polymer nanocomposite has shown great potential and impact on a broad range of techniques since its properties can be tailored by nano-fillers. This paper reports a polymer nanocomposite with enhanced electro-mechanical performance by mixing TiO2 nanoparticles into polydimethylsiloxane. Nanocomposites with particle concentration up to 30 wt% were prepared. High energy ball milling and polyether-modified silicone dispersant were used to suppress the agglomeration and ensure a stable dispersion. Properties of the nanocomposites, i.e. elastic modulus, response time, dielectric constant and optical transmittance, were tuned by modifying the particle concentration. Optimized electro-mechanical properties were observed at 5 wt% TiO2 particles. This nanocomposite was applied to a MEMS spatial light modulator, which was fabricated using micro-machining technology. The device was driven by a 200 V dc voltage and had a response time of 6 µs.

Preparation of Poly(4-vinylphenol)/Titanium Dioxide Composite and Its Application as a Gate Dielectric for Organic Thin-Film Transistors

Organic-inorganic composites can provide a unique feature combining superior dielectric properties of inorganic materials and solution processing capability of organic materials. In this study, poly(4-vinylphenol) (PVP) and titanium dioxide (TiO2) composite was prepared by mixing TiO2 nanoparticles in the PVP solution. In order to avoid severe gate-leakage currents in organic thin-film transistors (OTFTs) with such a composite gate dielectric layer, poly(oxyethylene)(20)-sorbitane monooleate was used as a surfactant for uniform dispersion of TiO2 particles. The dispersion stability of TiO2 nanoparticles in the composite solutions was confirmed by observing its sedimentation time in the composite solutions. The composite dielectric film, fabricated by means of simple spin-coating, provided an enhanced dielectric property and contributed to reducing the threshold voltage of OTFT, without augmenting the gate-leakage current. These results demonstrate that the fabricated composite dielectric film is essentially eligible for low-voltage operating OTFTs.