Synergistic enhancement in In2O3/In-MOM: Homologous heterojunction with engineered oxygen vacancies for ultrasensitive ethanol sensing

A novel chemical sensor featuring an In 2 O 3 -O v /In-nIm heterostructure was facilely fabricated through the in-situ growth of In 2 O 3 -O v on an In 3+ ions-based 2-nitroimidazole metal-organic material (In-nIm MOM). The proposed synthetic strategy effectively enhances the sensing performance. The oxygen vacancies provided by In 2 O 3 -O v can increase the number of reaction centers and active sites, and the abundant porous channels offered by the In-nIm are very beneficial for gas interaction and diffusion. As expected, the In 2 O 3 -O v /In-nIm gas sensor demonstrates outstanding performance, including ultrahigh sensitivity (9853) to 200 ppm ethanol at 230℃, rapid response/recovery speeds (2 s/6 s), an extremely low detection limit (0.003 ppb), superior selectivity, and robust stability. This work provides a potential strategy for fabricating advanced sensing materials by synergistically integrating the merits of metal oxide semiconductors and metal-organic materials, rendering the heterostructure a promising candidate for high-performance chemical sensors.