Construction of flexible BiOBr/W18O49/polyacrylonitrile discrete heterojunction nanofibers as a dual-functional photocatalyst for simultaneous hydrogen evolution and organic pollutant degradation

Dual-functional photocatalysis has attracted increasing attention due to its ability to achieve efficient synergistic hydrogen (H 2 ) evolution and pollutant removal. Energy band structure engineering and surface morphology modification of photocatalysts is a useful strategy to improve the activity of photocatalysis. This paper uses a combination of electrospinning technology and hydrothermal method to prepare flexible BiOBr/W 18 O 49 /PAN discrete heterojunction flexible nanofibers (NFs) with staggered energy bands and spatially separated redox surfaces. The BiOBr/W 18 O 49 heterojunction can improve carrier separation and migration, as evidenced by the photoluminescence and photoelectrochemical experiments. The localized surface plasmon resonance (LSPR) effect of W 18 O 49 can achieve injection of " hot electrons " and lead to expanding the light absorption range according to the UV - visible-near infrared diffuse reflection spectra results. The discrete structure of BiOBr/ W 18 O 49 /PAN NFs can provide spatially separated active sites for simultaneous photocatalytic redox reaction. As expected, the BiOBr/W 18 O 49 /PAN discrete heterojunction NFs greatly enhance the photocatalytic activity in simultaneous dual-functional reaction for H 2 evolution and RhB degradation. The highest simultaneous H 2 evolution rate and RhB degradation rate of BiOBr/W 18 O 49 /PAN NFs are 31.7 times and 34.1 times of BiOBr/ PAN, respectively. The design and construction of this flexible discrete heterojunction NFs structures can provide novel ideas and directions for simultaneous dual-functional photocatalysts.