▎ 摘　　要

A novel material synthesized by intercalating CrO3 in the multilayer graphene was used for the fabrication of reversible ammonia (NH3) gas sensor based on resistive transduction mechanism. Electron diffraction and X-ray diffraction revealed the formation of partial stage-2 CrO3 intercalated graphene. High resolution transmission micrographs showed the increase in the interlayer distances in graphene after intercalating CrO3 layers between graphene layers. Energy dispersive X-ray spectroscopy confirmed the presence of chromium and oxygen in the graphene layers. Current voltage studies using conducing atomic force microscopy showed the formation of junction between graphene and CrO3. Rapid and reversible sensing was observed when the CrO3-intercalated material was kept at 180 degrees. Sensor film demonstrated sensing response of 22.5% and 54% for 20 ppm and 50 ppm of NH3 at 180 degrees C. It took similar to 10 s for sensing NH3 gas and similar to 20 s for recovery on removal of gas. Reversible charge transfer between NH3 and electron deficient graphene connected to chromium trioxide at high temperature is proposed to be responsible for high selectivity and sensitivity of the intercalated material towards ammonia gas. The intercalated material showed > 8 months stability and sensing ability.