Synthesis of Atomically Thin WO3 Sheets from Hydrated Tungsten Trioxide.

Nanosheets of atomically thin WO3 layers are prepared by mechanical exfoliation of WO3·2H2O (obtained from pieces of tungsten foil in HNO3 at 80 °C for 6 h) using a piece of an adhesive tape, followed by annealing at 300 °C.