Designable Phase Transition Temperature of VO₂ Co-Doped with Nb and W Elements for Smart Window Application.

Monoclinic vanadium dioxide (VO₂ (M)) particles co-doped with niobium and tungsten, with potential application in smart windows, were synthesized by hydrolysis and subsequent thermal decomposition of vanadyl sulfate. All the doped VO₂ particles exhibited a monoclinic crystalline phase and the critical phase transition temperature () of VO₂ (M) was adjusted by Nb and W co-doping. The of Nb-doped VO₂ (M) decreased at a rate of approximately 10 °C/at% Nb dopant, and the transition temperature could also be accurately controlled to room temperature (about 27 °C) by co-doping with Nb and W.

Structural control of hierarchically-ordered TiO2 films by water for dye-sensitized solar cells.

A facile way of controlling the structure of TiO(2) by changing the amount of water to improve the efficiency of dye-sensitized solar cells (DSSCs) is reported. Hierarchically ordered TiO(2) films with high porosity and good interconnectivity are synthesized in a well-defined morphological confinement arising from a one-step self-assembly of preformed TiO(2) (pre-TiO(2)) nanocrystals and a graft copolymer, namely poly(vinyl chloride)-g-poly(oxyethylene methacrylate). The polymer-solvent interactions in solution, which are tuned by the amount of water, are shown to be a decisive factor in determining TiO(2) morphology and device performance.

Dual-functionalized mesoporous TiO(2) hollow nanospheres for improved CO(2) separation membranes.

Simultaneous improvement in CO2 permeability and CO2/N2 selectivity was obtained from mixed matrix membranes (MMMs) containing dual-functionalized mesoporous TiO2 hollow nanospheres (f-MTHS). Dual functionality resulted in the increased CO2 affinity and improved interfacial properties between inorganic nanofillers and the polymer matrix.

Multifunctional organized mesoporous tin oxide films templated by graft copolymers for dye-sensitized solar cells.

The synthesis of organized mesoporous SnO2 films with high porosity, larger pores, and good interconnectivity, obtained by sol-gel templating with an amphiphilic graft copolymer, poly(vinyl chloride)-graft-poly(oxyethylene methacrylate), is reported. An improved performance of dye-sensitized solar cells (DSSCs) is demonstrated by the introduction of a 400 nm thick organized mesoporous SnO2 interfacial (om-SnO2 IF) layer between nanocrystalline TiO2 (nc-TiO2 ) and a fluorine-doped tin oxide substrate. To elucidate the improved efficiency, the structural, optical, and electrochemical properties of the devices were characterized by SEM, UV/Vis spectroscopy, noncontact 3D surface profilometry, intensity-modulated photocurrent/voltage spectroscopy, incident photon-to-electron conversion efficiency, and electrochemical impedance spectroscopy measurements.

One-step synthesis of vertically aligned anatase thornbush-like TiO2 nanowire arrays on transparent conducting oxides for solid-state dye-sensitized solar cells.

Herein, we report a facile synthesis of high-density anatase-phase vertically aligned thornbush-like TiO2 nanowires (TBWs) on transparent conducting oxide glasses. Morphologically controllable TBW arrays of 9 μm in length are generated through a one-step hydrothermal reaction at 200 °C over 11 h using potassium titanium oxide oxalate dehydrate, diethylene glycol (DEG), and water. The TBWs consist of a large number of nanoplates or nanorods, as confirmed by SEM and TEM imaging.

Nanocomposites with graft copolymer-templated mesoporous MgTiO3 perovskite for CO2 capture applications.

Mesoporous MgTiO3 perovskite with a high porosity and interfacial properties were synthesized via a solvothermal reaction at 150 °C for 10 h using a graft copolymer, i.e., poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) with a well-ordered micellar morphology as a structure-directing agent.

Hybrid electrolytes prepared from ionic liquid-grafted alumina for high-efficiency quasi-solid-state dye-sensitized solar cells.

Alumina (Al2O3) nanoparticles were covalently surface-modified with an ionic liquid (IL) to improve their miscibility with ILs such as 1-methyl-3-propylimidazolium iodide (MPII). Hybrids consisting of MPII and the surface-modified IL-Al2O3 nanoparticles were utilized as an I2-free electrolyte for quasi-solid-state dye-sensitized solar cells (DSSCs). The synthesis and properties of the IL-Al2O3 nanoparticles and hybrid electrolytes were characterized by Fourier transform infrared (FT-IR) spectroscopy, UV-visible spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM).

Synthesis of low-cost, rubbery amphiphilic comb-like copolymers and their use in the templated synthesis of mesoporous TiO2 films for solid-state dye-sensitized solar cells.

Low-cost, rubbery amphiphilic comb-like copolymers consisting of hydrophobic poly(lauryl methacrylate) (PLMA) and hydrophilic poly(oxyethylene methacrylate) (POEM) were synthesized via one-step free radical polymerization. The synthesis of PLMA-POEM copolymers was confirmed using Fourier transform infra-red spectroscopy (FT-IR), (1)H-nuclear magnetic resonance ((1)H-NMR) and gel permeation spectroscopy (GPC). The PLMA-POEM copolymers were used as a structure-directing agent for the formation of anatase mesoporous TiO2 films.

Employing electrostatic self-assembly of tailored nickel sulfide nanoparticles for quasi-solid-state dye-sensitized solar cells with Pt-free counter electrodes.

A low cost, low-temperature processable, highly efficient nickel sulfide counter electrode is demonstrated. Using the tailored, preformed nickel sulfide nanoparticles and electrostatic self-assembly, a novel counter electrode was fabricated that exceeded the efficiency of a conventional Pt-based cell.

Direct assembly of preformed nanoparticles and graft copolymer for the fabrication of micrometer-thick, organized TiO2 films: high efficiency solid-state dye-sensitized solar cells.

Solid-state dye-sensitized solar cell with 7.1% efficiency at 100 mW/cm(2) is reported, one of the highest observed for N719 dye. Excellent performance was achieved via a graft copolymer-templated, organized mesoporous TiO(2) film with a large surface area using spindle-shaped, preformed TiO(2) nanoparticles and solid polymer electrolyte.

Preparation of TiO₂ nanowires/nanotubes using polycarbonate membranes and their uses in dye-sensitized solar cells.

Track-etched polycarbonate (PC) membranes were used as a soft template to synthesize mesoporous TiO(2) for use in dye-sensitized solar cells (DSSCs). The Ti precursor infiltrated into the cylindrical confined spaces of PC membranes. Upon calcination at 500 °C, TiO(2) nanowires (15TNW) were obtained from PC with a 15 nm pore diameter, whereas TiO(2) nanotubes (50TNT and 100TNT) were generated from PC with 50 and 100 nm diameter pores, respectively.

Graft copolymer directed synthesis of micron-thick organized mesoporous TiO2 films for solid-state dye-sensitized solar cells.

Micron thick, well-organized mesoporous TiO(2) films with high porosity and good connectivity were synthesized by templating an amphiphilic graft copolymer for solid-state dye-sensitized solar cells.

Polymer electrolytes based on grafted inorganic nanoparticles for dye-sensitized solar cells.

Inorganic nanoparticles such as TiO2 and SiO2 were grafted with poly(oxyethylene methacrylate) (POEM) and blended with poly(ethylene glycol) (PEG), 1-methyl-3-propylimidazolium iodide (MPII) and iodine (I2) to prepare polymer electrolytes for dye-sensitized solar cells (DSSC). The effects of the grafted nanoparticles on the coordination interactions and structures of electrolytes were investigated using FT-IR spectroscopy and differential scanning calorimetry (DSC). The energy conversion efficiencies were obtained as 3.