First‐Principles Study of the Effects of C/N/S Doping on the Magnetic and Photocatalytic Properties of a Bilayer Anatase TiO2 (001)

Most studies have theoretically and experimentally investigated the effects of single‐element C/N/S doping on the magnetic and photocatalytic properties of three‐dimensional TiO 2 . However, only a few comparative studies are available on the magnetic and photocatalytic properties of two‐dimensional anatase TiO 2 doped with C, N, or S. Based on the density functional theory framework, generalized gradient approximation + U method of the first principles is used to investigate the effects of doping three nonmetallic elements (C/N/S) on the magnetic and photocatalytic properties of bilayer anatase TiO 2 . The bilayer Ti 24 O 47 N (001) is found to have the lowest formation energy, the largest cohesion energy, is relatively stable, and exhibits magnetic property with a magnetic moment of −1.0 . The holes and electrons of Ti 24 O 47 N (001) system have longest carrier lifetime. The ratio of their average effective masses is 1.28, and the carrier separation in this system is good. The system is most favorable for the preparation of H 2 and O 2 from water decomposition. Within the 420–790 nm wavelength range, the Ti 24 O 47 N (001) system shows the strongest absorption spectrum intensity, the most prominent redshift, and the best activity. Thus, the bilayer Ti 24 O 47 N (001) system is an optimal photocatalyst.