| Autor: |
Alhawiti F; Physics Department, Lancaster University, Lancaster LA1 4YB, UK. q.wu6@lancaster.ac.uk.; Physics Department, Taif University, Kingdom of Saudi Arabia., Wu Q; Physics Department, Lancaster University, Lancaster LA1 4YB, UK. q.wu6@lancaster.ac.uk., Buceta D; Lab. Nanomag, Instituto de Investigaciones Tecnologicas, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain., Hou S; Physics Department, Lancaster University, Lancaster LA1 4YB, UK. q.wu6@lancaster.ac.uk., López-Quintela MA; Lab. Nanomag, Instituto de Investigaciones Tecnologicas, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain., Lambert C; Physics Department, Lancaster University, Lancaster LA1 4YB, UK. q.wu6@lancaster.ac.uk. |
| Abstrakt: |
Titanium dioxide (TiO 2 ) is an exceptional compound with unique optical properties, which have been intensively used for applications in photocatalysis. Recent studies show that Cu 5 atomic quantum clusters (AQCs) could facilitate visible light absorption and enhance the photocatalytic properties of rutile TiO 2 by creating mid-gap states. In this work, to move the theory of these catalysts closer to the experiment, we investigate the electronic structures of Cu 5 adsorbed on a perfect and reduced rutile TiO 2 surface in the absence and presence of silicate SiO 3 2- ions, which are introduced for the purification of Cu 5 AQCs. Encouragingly, our DFT simulations predict that the presence of SiO 3 2- does not reduce the gap states of the Cu 5 @TiO 2 composite and could even enhance them by shifting more states into the band gap. Our results also demonstrate that the polarons created by oxygen vacancies (O v ) and Cu 5 coexist within the band gap of TiO 2 . Indeed an O v behaves like a negative gate on the electronic states located on the AQCs, thereby shifting states out of the valence band into the band gap, which could lead to enhanced photocatalytic performance. |
