Hollow ZnWO4/In2O3 Nanotubes for Ultrasensitive and Rapid Trace Detection of Triethylamine

The directional modulation of metal oxide semiconductors (MOSs) can be effective in developing high-performance gas-sensing materials. Herein, we propose an efficient strategy by modifying ZnWO4 on In2O3 to achieve controllable modulation of oxygen vacancies and energy band structures in ZnWO4/In2O3 heterostructures. The sensor based on optimized ZnWO4/In2O3 exhibits significantly enhanced performance to detect triethylamine, including a lower operating temperature (100 °C), a higher responsivity (Ra/Rg = 221.2 for 100 ppm), and a lower detection limit (500 ppb). In addition, the fabricated sensor exhibits faster response and good selectivity. The improved gas-sensing performance could be attributed to the acid–base interaction between triethylamine gas and ZnWO4, the formation of heterojunctions, and the increase of oxygen vacancies to achieve a synergistic modulation of the chemical and energy band structures. It is anticipated that our current investigation could offer insights and a useful strategy for triethylamine detection.