Flower spherical-like Bi7O9I3/AgI S-scheme heterojunction for phenol photodegradation: The synergetic effect of dual surface plasmon resonance and photothermal property

The flower spherical-like S-scheme Bi7O9I3/AgI heterostructure was successfully fabricated through hydrothermal as well as calcination reduction method. The Ag and Bi nanoparticles generated during calcination reduction process are tightly fixed on surface of Bi7O9I3 and AgI, severally, which was distinctly beneficial to the charge transfer. On account of the enhanced light absorption and surface plasma resonance of Ag and Bi, Bi-Bi7O9I3/Ag-AgI possessed conspicuous photothermal effect. The results show that Bi-Bi7O9I3/Ag-AgI possessesed the optimal photodegradation efficiency and TOC removal rate of phenol, which are 100% and 95.38% within 80 min and 120 min. The light-induced carriers could be efficaciously separated by establishing an S-scheme photocatalytic system. A possible photocatalytic degradation mechanism of the as-constructed samples was investigated by free radical capture experiment as well as EPR technique. In addition, the photocatalyst exhibited the high stability. This work will supply a new perspective with the synthesis of novel S-scheme heterostructure.