Nanocrystalline Mesoporous Tin Dioxide Prepared by the Sol−Gel Route from a Dialkoxydi(β-Diketonato)tin Complex

Abstract

Nanocrystalline mesoporous tin dioxide materials have been obtained through the controlled hydrolysis of bis(2-methylbutan-2-oxy)di(pentan-2,4-dionato)tin followed by a thermal treatment at 400-550 °C. These materials have been carefully characterized by elemental analysis, FTIR, TGA-MS, XRD, MET, N 2 adsorption, and thermoporometry. They are composed of a porous network of aggregated nanoparticles with a mesoporosity arising from the interparticle space. A careful tuning of both hydrolysis ratio and calcination temperature allowed the preparation of powders with Brunauer-Emmett-Teller surface areas ranging from 50 to 150 m 2 ‚g -1 , an average pore size between 45 and 100 Å, and a mean particle size ranging from 60 to 180 Å. The higher hydrolysis ratio favored the formation of mesoporous solids with high surface areas and low mean pore size diameter. The powders prepared at 550 °C might be advantageously used as semiconducting oxide materials in dye-sensitized photovoltaic devices.

Alkynylorganotins, versatile precursors of class II hybrid materials

“…As a consequence, the mesoporosity detected by N 2 adsorption measurements could be attributed to the internanoparticle space as previously proposed for other SnO 2 materials prepared by sol-gel techniques. 31 By contrast, X 2b 500 showed a more complex morphology since it contained both nanoparticles, i.e. 10-30 nm, and much larger particles, the size of which was higher than 200 nm [ Fig.…”

Tin Dioxide Materials Chemically Modified with Trialkynylorganotins: Functional Nanohybrids for Photovoltaic Applications

“…Nanoporous SnO 2 powder (0.5 g) [16], first activated at 200°C for 2 h, and a solution of 0.02-0.6 mmol g -1 of 1, 2a, or 2b in CCl 4 or CH 2 Cl 2 (25 mL) were stirred for 16 h. After standing at room temperature for 4 h, the solution was removed, the modified powder was washed with CCl 4 or CH 2 Cl 2 (6 × 30 mL), and then dried at 60°C under reduced pressure (10 -3 mmHg, 1 mmHg ∼ 133 kPa) for 24 h. Two experiments were run in parallel for each experimental condition studied. The amount of chemisorbed fluorinated or perylene units was determined i) by comparison of the Fourier-transform IR (FTIR) spectra (integration of the CF 2 and CF 3 bands at 1243, 1215, and 1153 cm -1 for 1) or the UVvis absorption (absorption band at 445 nm for 2a and 2b) spectra of the grafting solution before and after reaction; ii) by elemental microanalysis of the hybrid material after drying.…”

“…Our strategy in this domain rests on the development of new routes towards nanoporous SnO 2 materials, [15] and the grafting of alkynylorganotins to create a Sn(oxide)-O-Sn-C(alkyl) linkage stable over a wide pH range. Thus, our group recently reported [16] the preparation of SnO 2 materials that consist of porous networks of aggregated nanoparticles with particle sizes ranging from 15 to 20 nm, which is the optimum size for photosensitization applications. [17] Furthermore, alkynyltins reacted with water or silanols to give oxides [18] or modified silica surfaces.…”

Thermal treatment synthesis of SnO2 nanoparticles and investigation of its light harvesting application

“…SnO 2 is a stable, n-type semiconductor with a wide band-gap (Eg = 3.6 eV). SnO 2 has excellent optical and electrical properties, such as fast electron conductivity and high stability [5][6][7]. Researches about SnO 2 -based dye-sensitized solar cells show low conversion efficiency of light-to-electrical power.…”