Rational design of MIL-88A(Fe)/Bi2WO6 heterojunctions as an efficient photocatalyst for organic pollutant degradation under visible light irradiation

Photocatalysis provides an exciting way to directly utilize solar energy to degrade environmental pollution. This process, however, suffers from rapid recombination of the photogenerated charges leading to low efficiency and instability. Herein, we report a novel MIL-88A(Fe)/Bi2WO6 heterojunction as a highly efficient photocatalyst for degradation of organic compounds under visible-light irradiation. When tested in 10 mg/L Rhodamine B (RhB), such catalyst can get remarkable degradation efficiency, up to 96%, at 50 min visible-light irradiation time. Significantly, it also shows super performance for Tetracycline (TC). Moreover, MIL-88A(Fe)/Bi2WO6 exhibited excellent photostability and recyclability. The superior photocatalytic activity of MIL-88A(Fe)/Bi2WO6 may be the formation of a heterojunction between MIL-88A(Fe) and Bi2WO6 with high surface area, which provides abundant active sites to drastically promote interactions between photocatalyst and reactants. Furthermore, the related electrochemical analysis and free radicals trapping experiments indicated that both center dot O-2(-) and h(+) have significant effect in the degradation process. Our findings of the work not only provide a novel insight to the design and develop MOF-based heterojunction photocatalysts but also suggest its great potential application value for environmental remediation.

Automated summary

A novel MIL-88A(Fe)/Bi2WO6 heterojunction was reported as a highly efficient photocatalyst for degrading organic compounds under visible-light irradiation, showing remarkable degradation efficiency and excellent photostability. The superior photocatalytic activity may be attributed to the heterojunction's high surface area and abundant active sites, with both center dot O-2(-) and h(+) playing significant roles in the degradation process.