Oxygen vacancy-enriched MoO3 hierarchical tubules via loofah sponge template for boosting high response triethylamine detection

Abstract

Monitoring triethylamine (TEA), a highly carcinogenic and explosive substance, is crucial for contemporary environmental governance and personal safety. However, achieving high-response TEA detection with MoO3-based sensors at low power consumption remains a challenge. Herein, biomimetic MoO3 hierarchical tubules synthesized via a biotemplate technology significantly enhance low temperature sensing performance for TEA vapor. After calcining a loofah sponge template simply impregnated with molybdate in air atmosphere at 500 °C, biomimetic MoO3 hierarchical tubules cross-linked by small sized nanosheets were successfully fabricated. The material exhibits a three-level mesoporous distribution, a relatively small bandgap, large specific surface area and abundant oxygen vacancy defects. Gas sensing tests reveal that at the optimized operating temperature of 133 °C, the MoO3-LS-5 sensor exhibits a high response value of 567 to 50 ppm TEA vapor and short response time of 5 s to 10 ppm TEA vapor. It also exhibits a low detection limit of 10 ppb, good selectivity and moisture resistance. Especially, the MoO3-LS-5 sensor can satisfactorily monitor the spoilage process of shrimp, demonstrating promising application potential in environmental and food safety monitoring. In addition, the detailed analysis of the response mechanism indicates that this outstanding sensitivity stems from the synergistic effect of the microstructural advantages of the tubular MoO3-LS-5 biomimetic material, the high concentration of active adsorbed oxygen and the catalytic action of surface vacant Mo6+ Lewis acid sites.