Platinum-silicon doped graphitic carbon nitride: A first principle calculation

Modifications of electronic and optical properties due to platinum, silicon, and platinum-silicon co-doping in the graphitic carbon nitride (g-C3N4) monolayer have been explored through density functional theory (DFT). The bandgap value of 1.2 eV has been obtained for the pristine g-C3N4 using generalized gradient approximation (GGA) employing Perdew-Burke-Ernzerhof (PBE) functional. The doping process has resulted in a fall in bandgap value. The platinum-silicon co-doping into g-C3N4 provides two new paths, C–N–Pt–N–C, and C–N–Si–N–C for the relocation of electron-hole couples across the adjacent heptazine rings. There is approximately a 25% increment (at 1 eV) in the optical conductivity in the infrared region after co-doping. The co-doped g-C3N4 also shows enriched light absorption. The work function is found to be decreased from 4.29 eV for the pristine g-C3N4 to 3.58 eV for the Pt/Si-co-doped g-C3N4. Hence, platinum-silicon co-doping should be considered as a suitable means to advance the photocatalytic performance of g-C3N4.