Pd-Loaded In2O3 Hollow Spheres with Enhanced Formaldehyde Sensing at Low Temperature

The porous Pd-loaded In 2 O 3 hollow spheres were successfully prepared by simple one-step method with the template of carbon spheres. The effect of calcination temperatures on morphology, composition and gas sensing performance of the as-obtained products was discussed by a series of test methods. The sample calcined at 550 ∘ C showed uniform porous hollow spheres with an average diameter of 100[Formula: see text]nm. Gas-sensing results exhibited that the Pd-In 2 O 3 hollow spheres-based sensor possessed excellent sensing properties to formaldehyde, which include high response value (33), low working temperature (180 ∘ C) and fast response and recovery time (12[Formula: see text]s and 22[Formula: see text]s). The enhanced HCHO-sensing properties of Pd-In 2 O 3 composites were attributed to the special porous and hollow structure, abundant oxygen vacancies and the catalysis of palladium. Pd-loaded In 2 O 3 hollow spheres had been proved to be an ideal material for detecting HCHO at a low working temperature.