Boosting H2S gas sensing performance of metal oxide semiconductors at room-temperature by the electron-extracting effect of Pt nanocluster

Hydrogen sulfide (H2S) is not only a hazardous gas harmful to environment, but is also a marker molecule for periodontitis. In this study, a sensitive H2S sensing chip was developed based on Pt nanocluster (NC) decorated TiO2@ZnFe2O4 nanotube arrays for room temperature (RT) operation. Benefiting from the plentiful defects induced by PtNC and the selectivity of ZnFe2O4 towards H2S, high sensing response and excellent specificity were achieved by the resulting sensing chips. The abundant energetic active defects (Ov and Pt+δ species) were mainly responsible for triggering the sensing reactions of H2S in the absence of traditional thermal energy and UV irradiation. Based on the excellent electron transfer properties and the electron-extracting effect of PtNC, the resulting samples exhibited a remarkably high sensitivity for H2S with a low limit of detection of 0.43 ppb and a response value of 16.6 towards 10 ppm H2S gas. This sensing chip also displayed good selectivity, reproducibility (RSD < 3 %), and long-term storage stability (RSD < 4 %). The successful application of PtNC provides a novel way to improve the sensing performance of metal oxide semiconductor-based chemiresistor gas sensors at RT.