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

Platinum nanoparticle (NP)-functionalized flower-like mesoporous SnO2 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 SnO2 nanoflowers upon physical mixing. The resulting Pt NP-decorated three-dimensional SnO2 mesoporous nanoflowers were incorporated into a gas sensor to detect H2S. The Pt-SnO2 sensor exhibited enhanced gas sensing properties toward H2S, with a 100 ppb detection limit, fast response, low working temperature, excellent stability, and good selectivity. The 0.3 wt% Pt-SnO2 sensor exhibited a high response and excellent selectivity to H2S at room temperature (response value to 5 ppm H2S at 30 degrees 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 H2S sensors. (C) 2020 Elsevier B.V. All rights reserved.