Electroless Plated SnO₂-Pd Thin Film For Room Temperature H₂ Detection

Hydrogen has excellent prospects as a clean energy, but the explosive nature of hydrogen causes a great obstacle to its application. Sensitive, effective and easy-to-use hydrogen sensors are needed to prevent hydrogen leak during the storage, transportation and use of hydrogen. SnO2 and Pd materials are commonly used in hydrogen sensors. Recently, extremely thin SnO2 nanosheets with high surface area was fabricated through a one-pot hydrothermal method. In this work, the gas sensing property of the SnO2 nanosheets was further explored. SnO2-Pd mixed thin films were prepared by electroless deposition of nanostructured SnO2 and Pd onto the surface of a high resistance alumina substrate. The whole fabrication process was carried out at room temperature without any further treatment required. It has been found that the SnO2-Pd sensor has a high response in the range of 100-1500 ppm toward hydrogen gas at room temperature with a short response time. The sensor also shows good repeatability. Effects of the composition (Pd/Sn ratio) of the sensing film, annealing condition and influence of humidity on the H2 gas sensitivity were investigated as well.