Engineered Sensitivity of Structured Tin Dioxide Chemical Sensors: Opaline Architectures with Controlled Necking

• Published in: Advanced functional materials 2003-03, Vol.13 (3), p.225-231
• Main Authors: Scott, R.W.J., Yang, S.M., Coombs, N., Ozin, G.A., Williams, D.E.
• Format: Article
• Language: English
• Subjects: chemical; Inverse opals; Inverse opals, polymer; Micromolding; Opaline lattices; polymer; Sensors; Sensors, chemical; Tin oxides
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.200390034

Structure–property relationships in tin dioxide materials have been studied utilizing a reverse templating strategy to synthesize opaline structures with controlled neck dimensions between spheres. The necking dimensions could be controlled by sintering the parent silica opals at temperatures between 700 and 1050 °C. Inverted polymer opals were synthesized by infiltrating the silica opals with styrene, followed by thermally induced polymerization, and removal of the silica with HF. Tin dioxide opals with controlled microstructures were then synthesized from these inverted polymer opals. The gas sensing response of these materials to carbon monoxide could be understood as a function of the necking diameter in the resulting tin dioxide opals. Tin dioxide opals have been fabricated utilizing a reverse templating strategy (see Figure, an electron microscopy image of the opals). The neck diameter between spheres in the SnO2 opals can be controlled by variable sintering of the parent silica opals at temperatures between 700 and 1050 °C. The sensor response of the SnO2 opals towards carbon monoxide has been examined and can be understood as a function of the final neck diameter.