Effects of hydrogen treatment on the triethylamine-sensing properties of the platinum-loaded In2O3 nanosheets

In this work, platinum-loaded In2O3 (Pt/In2O3) nanosheets were synthesized and their triethylamine (TEA) sensing performance was improved by hydrogen treatment. The response of 0.25 Pt/In2O3 (H2) to 100 ppm TEA was as high as 4792, which was 12 times the untreated one. The detection limit of 0.25 Pt/In2O3 (H-2) was 50 ppt. The samples before and after hydrogen treatment were analyzed by various techniques. It was found that the supported Pt had a high degree of dispersion. Even after hydrogen treatment, most Pt in the 0.25 Pt/In2O3 (H-2) existed in the form of single atoms. Pt loading and hydrogen treatment can improve the electron mobility of In2O3. Besides, after hydrogen treatment, the number of low-valence Pt increased, which promoted the generation of adsorbed oxygen and reduced the TEA response energy barrier, thereby enhancing the sensitivity to TEA. These findings are significant for the design of supported metal sensing materials and show the importance of hydrogen treatment in improving the response of Pt-loaded sensing materials and the crucial role of low-valence Pt in TEA sensing performance.