Bimetallic AuPt alloy nanoparticles decorated on ZnO nanowires towards efficient and selective H2S gas sensing

The development of high-performance H 2 S sensor is imperative for monitoring H 2 S in the living environment. Metal oxide semiconductors (MOSs) have been regarded as the strongest candidates for H 2 S detection due to their high sensitivity, miniaturization, and good durability. However, a single MOS-based gas sensor is unable to selectively detect gases, which limits its practical application. Functionalization of noble metal nanoparticles (e.g., Pt, Pd, and Au) on the surface of MOS can improve its selectivity. Herein, ZnO nanowires decorated with AuPt bimetallic nanoparticles are designed and fabricated on MEMS for H 2 S detection. The AuPt@ZnO nanowires-based sensor shows a response of 17.7–20 ppm H 2 S at 300 °C which is 4.0 times higher than that of pristine ZnO nanowires-based sensor. The sensor also exhibits a rapid response-recovery process, brilliant long-term stability, and excellent selectivity to H 2 S among various interfering gases. The remarkable improvement of the sensing performance, especially selectivity, could be ascribed to the electronic and chemical sensitization and the synergistic effect of the AuPt bimetal. Thus, the AuPt@ZnO nanowires-based sensor has a great potential application for H 2 S detection. • The AuPt@ZnO nanowires were synthesized by a hydrothermal method and reduction treatment. • The AuPt@ZnO-based sensor towards H 2 S was prepared via simply dropping the AuPt@ZnO nanowires solution on the MEMS. • The AuPt@ZnO-based sensor exhibited high response, excellent selectivity and short response time towards H 2 S. • The electronic and chemical sensitization and the synergistic effect of the AuPt bimetal could improve sensing properties.