Synthesis and low temperature methane sensing performance of Pd modified In2O3 microspheres

This paper investigated the methane (CH4) gas sensing performance of Pd/In2O3 composites, fabricated by a simple solvothermal method. The morphology, composition and nanostructure of the synthesized materials were characterized and analyzed by XRD, FESEM, TEM, EDS and XPS. Compared with the pure In2O3, 6.0 at% Pd/In2O3 microspheres presented a better gas sensing performance to CH4. The response value of 6.0 at% Pd/In2O3 microspheres to 500 ppm CH4 was 15.317 at 50 °C. Besides, the sensor based on 6.0 at% Pd/In2O3 has a low detection limit (as low as 1.78 ppm). At the same time, the sensor has good selectivity, reproducibility and long-term stability. The enhanced gas sensing performance could be mainly ascribed to chemical catalysis and spillover effects of Pd nanoparticles as well as the Schottky Barrier between Pd and In2O3.