Understanding the influence of single metal (Li, Mg, Al, Fe, Ag) doping on the electronic and optical properties of g-C₃N₄: a theoretical study

ABSTRACT

Semi-empirical tight-binding-based quantum chemistry method (GFN2-xTB) has been done to study the influence of single metal (Li, Mg, Al, Fe, Ag) doping on the electronic and optical properties of monolayer corrugated graphitic carbon nitride (g-C₃N₄). Based on the calculated formation energy and population analysis, we showed that the metal atom is chemically bound to the g-C₃N₄ surface. The metal doping reduces the vertical ionisation potential and raises the electron affinity and Lewis acidity of g-C₃N₄. The metal-doped g-C₃N₄ systems have lower band gap than that of pristine g-C₃N₄ which is attributed to the electron donating from the metal atom to g-C₃N₄. Analysis of the lowest unoccupied molecular orbital and the highest occupied molecular orbital shows that for the Fe- and Ag-doped g-C₃N₄ systems the separation of photo-generated electron–hole pairs is efficient, resulting in the enhancement of photo-catalytic activity.

KEYWORDS:

• GFN-xTB
• g-C₃N₄
• GEI
• FOD
• band gap

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) [grant number 05/2018/TN].