Fabrication of UV-Vis-NIR-driven photocatalysts Ag/Bi/BiOCl0.8Br0.2 with high catalytic activity

In this work, multiple heterojunction Ag/Bi/BiOCl0.8Br0.2 photocatalysts with novel porous micro-flower structure were fabricated via a facile one-step solvothermal route and characterized systematically. The TEM and HRTEM images clearly showed the heterogeneous nanostructures at the interface between Ag/Bi and BiOCl0.8Br0.2. The as-prepared Ag/Bi/BiOCl0.8Br0.2 composites displayed a strong optical absorption in the region of 250-1500 nm, especially in the unexploited near infrared region which accounts for most of the sunlight. The multiple heterojunction photocatalyst exhibited an outstanding photocatalytic activity for the degradation of Rhodamine B under the UV, visible and NIR light irradiation, respectively. The highly enhanced photocatalytic activity was attributed to the synergistic effects, including the reduced band gap, the surface plasmon resonance effect, efficient charge separation of photo-generated electron-holes. On the basis of the radical species trapping experiments, the holes and superoxide radicals were confirmed to be the mainly active species involved in the degradation of Rhodamine B under the NIR light irradiation. This study provides a novel strategy for designing highly performance plasmonic photocatalysts under the whole solar light irradiation.