Pd/Pt-Bimetallic-Nanoparticle-Doped In2O3 Hollow Microspheres for Rapid and Sensitive H2S Sensing at Low Temperature

Abstract

H2S is a poisonous gas that is widespread in nature and human activities. Its rapid and sensitive detection is essential to prevent it from damaging health. Herein, we report Pd- and Pt-bimetallic-nanoparticle-doped In2O3 hollow microspheres that are synthesized using solvothermal and in situ reduction methods for H2S detection. The structure of as-synthesized 1 at% Pd/Pt-In2O3 comprises porous hollow microspheres assembled from In2O3 nanosheets with Pd and Pt bimetallic nanoparticles loaded on its surface. The response of 1 at% Pd/Pt-In2O3 to 5 ppm H2S is 140 (70 times that of pure In2O3), and the response time is 3 s at a low temperature of 50 °C. In addition, it can detect trace H2S (as low as 50 ppb) and has superior selectivity and an excellent anti-interference ability. These outstanding gas-sensing performances of 1 at% Pd/Pt-In2O3 are attributed to the chemical sensitization of Pt, the electronic sensitization of Pd, and the synergistic effect between them. This work supplements the research of In2O3-based H2S sensors and proves that Pd- and Pt-bimetallic-doped In2O3 can be applied in the detection of H2S.

Approaches for selectivity improvement of conductometric gas sensors: an overview

“…[42][43][44] In addition, compared to single metal doping, bimetallic doping probably exhibits synergistic effects due to geometric effects, electronic interactions, and chemical reactions, which can simultaneously catalyze and sensitize the parent material, and thus improve the selectivity. For instance, K. Jiang et al 42 reported Pd/Pt bimetallic-NP-doped In 2 O 3 hollow microspheres that were synthesized using solvothermal and in situ reduction methods for H 2 S detection. It was found that 1 at% Pd/Pt In 2 O 3 composites exhibit strong selectivity and sensing performance (as shown in Fig.…”