The BiOBr/Bi/Bi2WO6 photocatalyst with SPR effect and Z-scheme heterojunction synergistically degraded RhB under visible light

Metal surface deposition and construction of heterojunctions are the primary methods for increasing photocatalytic activity and improving solar energy utilization. Herein, we have successfully prepared a BiOBr/Bi/Bi2WO6 ternary composite photocatalyst for the photocatalytic degradation of Rhodamine B (RhB) under visible light using a facile hydrothermal method. The results showed that after 60 min of visible light irradiation, the 20%BiOBr/7%Bi/Bi2WO6 could degrade RhB as high as 98.02%, which was 1.75 times and 1.53 times that of Bi2WO6 and 7%Bi/Bi2WO6, respectively. This significantly enhanced photocatalytic performance is due to the surface plasmon resonance (SPR) effect of Bi metal and the synergistic effects of BiOBr and Bi2WO6 Z-scheme heterojunction. After four cycles, the degradation efficiency of the 20%BiOBr/7%Bi/Bi2WO6 for RhB decreased slightly by 10.69%. Furthermore, free radical and hole scavenging experiments in the photocatalytic process revealed that the hole (h+) played an indispensable role. Finally, using systematic experimental evidence, a possible mechanism for the photocatalytic enhancement of the composite was proposed.