Violet phosphorus nanosheets for room-temperature dimethylamine detection and mechanism insights by DFT calculation

Two-dimensional (2D) materials offer great prospects in room temperature (RT) gas sensors with minimum power consumption, compared to conventional metal oxide semiconductor sensors that require high temperature operation. In this work, we prepared violet phosphorus (VP) nanosheets by optimized liquid-phase exfoliation in various solvents. A highly sensitive gas sensor has been fabricated by using the prepared VP nanosheets for detection of dimethylamine (DMA), a toxic chemical widely used in various industries. The VP sensor shows an ultrafast response time of ∼2 s and high response to DMA at RT. The sensing mechanism has been analyzed by density functional theory calculations, revealing significant electron transfer from DMA to VP. This work explores the promise of VP in low power sensors.