Investigation of the H2 sensing properties of multilayer mesoporous pure and Pd-doped SnO2 thin film

Abstract

Multilayer mesoporous pure and Pd-doped SnO2 thin films had been successfully synthesized through an evaporation induced self-assembly (EISA) method using Pluronic F127 as template and deposited by an improved spin-coating method. The crystalline structure and micro morphology of the prepared materials were analyzed. The specific surface area and average pore size of mesoporous SnO2 were 90.61 m2/g and 4.89 nm, respectively. The average crystallite size was about 6 nm for mesoporous SnO2. The H2 sensing properties were investigated to different H2 concentrations and at different temperatures. The response magnitude of the five-layer pure mesoporous SnO2 thin film to 1000 ppm H2 at 175 °C was 237.85. This amount was approximately 4.11 times that of single layer sample. The correlation of the response magnitude and H2 concentration of the five-layer pure mesoporous SnO2 thin film was more linear compared to the five-layer Pd-doped mesoporous SnO2 thin film, which had the highest response magnitude of 774.49–1000 ppm and 1115.39–2000 ppm H2 at 175 °C. The response and recovery behavior was discussed and the mechanism of the outstanding H2 sensing performance was explained.