Fig. 5.

a Optimized atomic structure of S-doped mesoporous CN (S-MCN). b Charge density profile of S-MCN, blue color—lowest electron density (0%), and red color—highest electron density (100%). Reproduced with permission from Ref. [31]. c Optimized structure g-C₃N₄ monolayer, showing possible P-doping sites. d DOS plots of P-doped g-C₃N₄ for P substitution at N1 and N2 sites. Reproduced with permission from Ref. [32]. Copyright permissions from American Chemical Society and Springer Nature. (Color figure online)