Structural design of highly permeable Bi₂O₃ microspheres decorated by Pt-nanoparticles: facile synthesis and acetic acid sensing performance

Real-time detection of acetic acid vapor is of concern for ensuring environmental and personal safety. However, acetic acid gas sensors, particularly those based on Bi₂O₃, often fail to meet practical performance requirements owing to their slow response characteristics and high operating temperature. To enhance sensing performance, highly permeable Bi₂O₃ microspheres decorated by Pt-nanoparticles are rationally synthesized by a facile template method. Among the fabricated sensors, the one based on 3 wt% Pt-decorated Bi₂O₃ demonstrated excellent sensing performance. Specifically, the sensor displayed high selectivity for acetic acid, rapid response and recovery times (22.5 and 9 s, respectively), strong resistance to interference, and good long-term stability at a low operating temperature (150 °C). Notably, the sensor exhibited an exceptionally high response of 126 to 100 ppm acetic acid—the highest reported value for Bi₂O₃-based sensors tested at a relatively low operating temperature in recent years. These results demonstrate that Pt-decorated Bi₂O₃ holds strong potential for use in high-performance acetic acid sensors.