Enhanced interfacial charge transfer and photothermal effect via in-situ construction of atom co-sharing Bi plasmonic/Bi4O5Br2 nanosheet heterojunction towards improved full-spectrum photocatalysis

Constructing a plasmonic heterojunction photocatalyst is a prospective approach to improve full-spectrum photocatalytic performance. However, low interfacial charge transfer efficiency due to lattice mismatch severely limits its photocatalytic performance. Herein, a Bi atom co-sharing Bi/Bi4O5Br2 plasmonic heterojunctions were fabricated via in-situ reduction. Experimental characterizations and theoretical calculations demonstrate that the co-sharing Bi atom enables intimate contact in the heterointerface, significantly promoting interfacial charge transfer and separation. In addition, Bi metal's surface plasmon resonance effect extends the photoresponse to the near-infrared region and enhances the photothermal performances, significantly improving solar energy's utilization efficiency. By these prominent features, the optimized Bi/Bi4O5Br2 heterojunctions show that the photocatalytic degradation ratio of BPA reaches 100 % within 40 min under full-spectrum irradiation, which is about three times higher than that of Bi4O5Br2. Moreover, the photocatalytic efficiency was significantly increased by 7.5 times with the increase in temperature under NIR light irradiation due to the photothermal effect. This work offers new insights into the rational design of low-cost, highly efficient, and stable Bi-based plasmonic heterojunction photocatalysts for full solar spectrum utilization by integrating plasmonic nanostructures and photothermal effect.