Sulfur vacancy-rich ZnIn2S4 microflower with {0001} facets for rapid sensing of triethylamine

Two-dimensional (2D) layered metal sulfides with abundant edge sites and weak van der Waals bonds are promising materials that absorb sensing molecules at low temperatures. The introduction of defects is an effective strategy to improve the sensing performance of two-dimensional sulfide semiconductors. In this experiment, we used a facile hydrothermal method to adjust the S content of the lattice in ZnIn2S4 microflowers (MFs). And the ZnIn2S4 MFs with suitable S-vacancy content were derived from the precursor with a stoichio-metric ratio (Zn/In/S) of 1:2:6. These S-defect-engineered controlled growth of ZnIn2S4 MFs is composed of many nanosheets(NSs) with exposed {0001} facets grown along the c-axis direction, which has a large number of S -vacancies that can serve as active sites for sensing reactions. Thus, S-vacancy-rich ZnIn2S4 MFs exhibited better sensing performance for triethylamine even at the optimum operating temperature(90 celcius), including high response(1013-100 ppm), low limit of detection(1 ppm), excellent gas selectivity, and fast response(4 s). It also shows good sensitivity to lower concentrations of triethylamine at room temperature. This work demonstrates the good effect and potential of vacancy modulation in improving the performance of two-dimensional sulfide nanomaterials for low-power sensing.