ABSTRACT
We investigate mechanical, structural and electronic properties of CO2 adsorbed graphitic carbon nitride (g-C3N4) system under biaxial tensile strain via first-principles calculations. The results show that the stress of CO2 adsorbed g-C3N4 system increases and then decreases linearly with the increasing biaxial strain, reaching maximum at 0.12 strain. This is primarily caused by the plane N-C stretching of the g-C3N4. Furthermore, both the Perdew-Burke-Ernzerhof (PBE) and Heyd- Scuseria-Ernzerhof screened hybrid functional (HSE06) band gaps show direct-indirect transitions under biaxial tensile strain and have the maximum also at 0.12 strain. It is found that there is large dipole transition matrix element around Γ point, leading high optical absorption coefficients of the deformed adsorption system, which would be of great use for the applications of new elastic nanoelectronic and optoelectronic devices.
ABSTRACT
We report first-principles calculations on the structural, mechanical, and electronic properties of O2 molecule adsorption on different graphenes (including pristine graphene (G-O2), N(nitrogen)/B(boron)-doped graphene (G-N/B-O2), and defective graphene (G-D-O2)) under equibiaxial strain. Our calculation results reveal that G-D-O2 possesses the highest binding energy, indicating that it owns the highest stability. Moreover, the stabilities of the four structures are enhanced enormously by the compressive strain larger than 2%. In addition, the band gaps of G-O2 and G-D-O2 exhibit direct and indirect transitions. Our work aims to control the graphene-based structure and electronic properties via strain engineering, which will provide implications for the application of new elastic semiconductor devices.
