Synthesis and room-temperature H2S sensing of Pt nanoparticle-functionalized SnO2 mesoporous nanoflowers

Platinum nanoparticle (NP)-functionalized flower-like mesoporous SnO 2 with a high specific surface area (31.6 m 2 g –1 ) and large pore diameter (32.5 nm) was synthesized using a double-template technique. The presence of Pt NPs was confirmed by X-ray photoelectron spectroscopy. Pt NPs with a size distribution of 2–4 nm were anchored on mesopores of the pre-synthesized three-dimensional SnO 2 nanoflowers upon physical mixing. The resulting Pt NP-decorated three-dimensional SnO 2 mesoporous nanoflowers were incorporated into a gas sensor to detect H 2 S. The Pt–SnO 2 sensor exhibited enhanced gas sensing properties toward H 2 S, with a 100 ppb detection limit, fast response, low working temperature, excellent stability, and good selectivity. The 0.3 wt% Pt–SnO 2 sensor exhibited a high response and excellent selectivity to H 2 S at room temperature (response value to 5 ppm H 2 S at 30 °C was 160). The significant improvements in gas sensing properties were attributed to the synergistic effect of the mesoporous nanostructure induced by the double-template method and the catalytic sensitization of the Pt NPs. These findings offer guidance for designing mesoporous materials and low-temperature H 2 S sensors.