High-performance octahedral Zn2SnO4 gas sensor for rapid acetone detection

Rational design of the morphology and defect structure of gas-sensing materials can significantly enhance the gas-sensing performance of Metal oxide semiconductor (MOS). In this work, three different morphologies of Zn₂SnO₄ were successfully synthesized by adjusting the amount of LiOH. Systematic characterization reveals that increasing the LiOH concentration not only induced the morphological evolution of Zn₂SnO₄, but also effectively modulated its specific surface area (SSA) and oxygen-vacancy (O_vac) concentration. The octahedral Zn₂SnO₄ (ZSO-O) exhibits the largest SSA (149.62 m²·g⁻¹), (111) crystal plane and the highest O_vac concentration, thereby offering abundant active sites for gas adsorption and surface reactions. Consequently, the ZSO-O sensor exhibits the best performance in acetone detection, including the highest response value (100 ppm: 30.7), fast response ability (1s), good selectivity and stability. The performance improvement is attributed to the synergistic interaction between its unique morphology and defects. This study presents a simple and effective strategy to achieve morphology-defect synergy in spinel Zn₂SnO₄, and highlights its potential as a high-performance acetone gas-sensing device for environmental monitoring.