State Key of Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing, Jiangsu 210009, People's Republic of China.
Nanoscale. 2011 Oct 5;3(10):4283-9. doi: 10.1039/c1nr10678c. Epub 2011 Aug 30.
High surface area highly ordered nanoporous thin films are the current gold standard for gas sensor use, however the nanostructure of such films is prone to collapse at annealing temperatures as low as 250 °C resulting in formation of a dense layer of limited utility. We report on a templating method used to deposit highly ordered nanoporous platinum (Pt)-doped tin dioxide (SnO(2)) thin films that are crystallized by a 100 °C water vapor hydrothermal treatment, with the low temperature process being compatible with a large variety of substrates including plastic. The resulting highly ordered nanoporous, transparent Pt-SnO(2) thin films are mechanically stable and can be annealed, as desired, at temperatures up to 800 °C for removal of the templating materials and tailoring of gas sensitivities without damage to the nanoporous structure. The synthesis method is general, offering a promising strategy for preparing high performance nanoporous metal oxide crystalline films for applications including gas sensing, photocatalysis, and 3(rd) generation photovoltaics. In our example application of the synthesized materials, we find that these Pt-SnO(2) films exhibit exceptional hydrogen gas sensing behavior, rapidly detecting low-level hydrogen concentrations at room temperature; for example, an eight order of magnitude change in electrical resistance is seen in response to 10 000 ppm H(2), with only minimal sensitivity to humidity.
高比表面积的高度有序纳米多孔薄膜是目前用于气体传感器的黄金标准，然而，这种薄膜的纳米结构在低至 250°C 的退火温度下容易坍塌，导致形成一层致密的、用途有限的层。我们报告了一种用于沉积高度有序的纳米多孔铂（Pt）掺杂氧化锡（SnO2）薄膜的模板法，该薄膜通过 100°C 水蒸气水热处理结晶，低温工艺与多种基底兼容，包括塑料。所得的高度有序的纳米多孔、透明的 Pt-SnO2 薄膜在机械上是稳定的，可以根据需要在高达 800°C 的温度下退火，以去除模板材料并调整气体敏感性，而不会损坏纳米多孔结构。该合成方法具有普遍性，为制备用于气体传感、光催化和第三代光伏等应用的高性能纳米多孔金属氧化物晶态薄膜提供了有前途的策略。在我们合成材料的示例应用中，我们发现这些 Pt-SnO2 薄膜表现出优异的氢气传感行为，能够在室温下快速检测低浓度的氢气；例如，在 10000 ppm H2 的响应中，电阻会发生八个数量级的变化，对湿度的敏感性最小。
