Facet Engineering of BiVO4 Polyhedra Enables Synergistic Enhancement of Sensitivity with Suppressed Humidity Interference for Glutaraldehyde Sensing.

Due to its broad-spectrum sterilization ability, glutaraldehyde is widely used for sterilizing medical devices. However, a certain concentration of glutaraldehyde gas in the air can cause harm to the health of medical staff and patients. Due to the long-chain nature of glutaraldehyde and the interference of humidity in the detection environment, its detection is challenging. In this study, octadecahedral BiVO4 (Octad-BiVO4) with multiple crystal facets was synthesized through crystal facet engineering. Compared with other structures of BiVO4, this structure simultaneously achieved the dual effects of active site enrichment and humidity interference suppression, enabling the Octad-BiVO4 glutaraldehyde gas sensor to exhibit excellent gas sensing performance even under humidity conditions close to those of actual indoor applications. Through XPS, dangling bond calculations and density functional theory calculations, the differences in oxygen vacancies, unsaturated coordinating atoms, and adsorption energy for glutaraldehyde among different crystal facets were revealed. It confirmed the influence of crystal facet engineering on gas sensing performance. Additionally, this work also designed a portable monitoring circuit system for glutaraldehyde, which can not only provide real-time concentration alarms for glutaraldehyde but also transmit information via Bluetooth to the terminal. This work provides a new strategy for detecting trace amounts of glutaraldehyde gas under humid conditions.