Boron-Decorated\nGraphitic Carbon Nitride (g‑C₃N₄): An\nEfficient Sensor for H₂S, SO₂, and NH₃ Capture

Abstract

We investigated the interactions between nonboron (g-C₃N₄) and boron-decorated (B-g-C₃N₄) graphitic carbon nitride complexes with H₂S,\nSO₂, and NH₃ molecules by first-principles calculations.\nOur results show a highly superior selectivity toward the H₂S gas compared to the SO₂ molecule. In addition, by increasing\nthe concentration of nitrogen defects at the edges of g-C₃N₄ from 1.785 to 3.572%, we noticed a complete H₂S dissociation, with the two hydrogen atoms chemisorbed on the g-C₃N₄ planes while the sulfur atom (S) remained in\nthe gaseous phase. However, the efficiency of the D site is altered\nby the gas–gas interaction where a partial dissociation of\nH₂S occurs. Furthermore, our results show that doping g-C₃N₄ with the B atom was very efficient to fix the\nS atom on the g-C₃N₄ substrate. Moreover, decorating\nthe g-C₃N₄ edges with the B atom enhanced selectivity\ntoward the H₂S, SO₂, and NH₃ gases\nas they strongly chemisorbed on the B-g-C₃N₄ complex. Furthermore, our results in the gas–gas interaction\nshow the same trend as the earlier results reported for a single gas\nadsorption. These results predict that B-g-C₃N₄ may be a better sensor for H₂S, SO₂, and NH₃ compared to pure and nitrogen monovacancy defect g-C₃N₄.