ZnIn 2 S 4 Nanosheets for Efficient NO 2 Detection at Room Temperature: Insights into the Role of Sulfur Vacancies.

Engineering atomic vacancies in metal sulfide semiconductors allows for the efficient tuning of their electronic and chemical properties. In this work, we synthesized hollow tubular structures constructed by bimetallic ZnIn 2 S 4 using a metal-organic framework (MOF) as the template. We found that the sulfur vacancies in ZnIn 2 S 4 enabled extremely fast NO 2 detection with high response at room temperature (RT), and the material with high sulfur vacancy content delivers a 2 times higher response to 10 ppm NO 2 than the device with low sulfur vacancy content. To unveil the crucial role played by sulfur vacancies, DFT calculations were conducted to reveal that sulfur vacancies greatly enhance the interaction and electron transfer between ZnIn 2 S 4 and NO 2 . This study will provide hints for the engineering of bimetallic sulfide materials for low-power gas sensors at RT.