Enhanced charge transfer in 2D carbon- rich g-C3N4 nanosheets for highly sensitive NO2 gas sensor applications

Two-dimensional (2D) materials have fascinated tremendous attention in many areas of the research field. Especially, the gas sensor is considered as a promising application in utilizing 2D materials. Recently, Graphitic carbon nitrides (g-C3N4) have sparked wide attention in the research due to their performance in chemiresistive gas sensing properties. Herein, pristine g-C3N4 and C/g-C3N4 (carbon enrich-graphitic carbon nitride) were prepared via a polycondensation process. Structural and elemental analysis confirms the formation of C/g-C3N4. High-Resolution Scanning Electron Microscopy and High-Resolution Transmission Electron Microscopy revealed the sheet-like morphology with more number of active sites. The NO2 gas sensing performance of the sensor based on C/g-C3N4 were systematically studied. The response of the C/g-C3N4 sensing films has significantly enhanced compared to the pristine g-C3N4. The maximum sensor response is attained for 10 wt% of C/g-C3N4 with 71.36 % towards 50 ppm of NO2 at 200 degrees C. The gas sensing response of 10 wt% C/g-C3N4 showed 3 times more enhancement than the pristine g-C3N4. This study revealed the development of a highly sensitive gas sensor for next-generation toxic gases detection.