Pd-loaded SnO hierarchical nanospheres for a high dynamic range HS micro sensor.

Herein, a high dynamic range HS micro gas sensor was achieved using hierarchical Pd-loaded SnO nanostructures as a sensing material. SnO nanospheres were synthesized using a hydrothermal method without any surfactants or templates, followed by Pd nanoparticle decoration a facile method. A hierarchical nanostructure of Pd-loaded SnO was formed, and its sensing abilities were compared with those of pure SnO nanosphere-based sensors. The Pd-loaded SnO hierarchical nanostructures showed an ultra-sensitive HS detection ability down to 10 ppb, a high dynamic range (4 orders of magnitude) up to 200 ppm, and a low working temperature (150 °C). Thus, this micro gas sensor based on Pd-loaded SnO hierarchical nanostructures has promising applications in universal HS detection. The fabrication method presented herein is simple, renewable and operable and thus may be extended to synthesize other types of metal oxide-based semiconductor micro sensors for application in various fields.