▎ 摘　　要

The electronic and adsorption properties of the zigzag-edged triangle graphene nanosheets with different size are investigated, including the calculation of the adsorption energy, sensitivity and recovery time after adsorbing CO2, NO2, CH4 and CO. The results show that the quantum size effect is satisfied in the triangle graphene nanosheets, and its conductivity type can be changed from p to n. In addition, the triangle graphene nanosheets with n = 5 has the highest sensitivity to NO2 (374.79%), which is more than 300 times as compared to the lowest one. The recovery time of triangle graphene nanosheets with n = 4 is the shortest, and its sensitivity and recovery time are the best at 144 K. These results reveal that the zigzag-edged triangular graphene nanosheets can serve as the fundamental structural unit for the design of high sensitivity gas sensors.