Tailoring S-scheme-based carbon nanotubes (CNTs) mediated Ag-CuBi 2 O 4 /Bi 2 S 3 nanomaterials for photocatalytic dyes degradation in the aqueous system

In this study, S-scheme-based hydrothermal synthesis of Ag-CuBi 2 O 4 /CNTs/Bi 2 S 3 layered composites has been successfully reported. The photo-degradation of toxic dyes, viz. methyl orange (MO), and methylene blue (MB), has been used to examine nanocomposites with varying weight percent of Bi 2 S 3 for photocatalytic activity in the visible range. Among candidates, Ag-CuBi 2 O 4 /CNTs/Bi 2 S 3 with a 10% loading of Bi 2 S 3 outperformed both pure and hybrid composites in photocatalytic activity. For MO degradation, the hybrid composite with 10% Bi 2 S 3 loading degrades 7.04 times higher than pristine CuBi 2 O 4 and Bi 2 S 3 samples, and for MB degradation, it degrades 4.96 times higher than pristine samples. High surface area, less recombination rate of photogenerated charge carriers, photogenerated carriers faster separation, and high redox ability of Ag-CuBi 2 O 4 /CNTs/Bi 2 S 3 (10%) are all attributed to the improving photocatalytic performance. Even after ten cycles, the hybrid composite is chemically stable and reusable. Carbon nanotubes (CNTs) are a transfer bridge in layered structure for electrons because of their coordinated Fermi level between Ag-CuBi 2 O 4 and Bi 2 S 3 . In addition, the scavenger and electron spin resonance (ESR) experiments verified that center dot O 2 -, center dot OH, and h + were the important reactive species that successfully facilitated the photocatalytic degradation process to degrade dyes. This study presents a straightforward and economical approach for obtaining a stable semiconductor-based photocatalytic system and a potential technique for future applications.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

This study successfully reported the S-scheme-based hydrothermal synthesis of Ag-CuBi2O4/CNTs/Bi2S3 layered composites. The photocatalytic activity of nanocomposites with varying weight percent of Bi2S3 for the degradation of methyl orange (MO) and methylene blue (MB) dyes in the visible range was examined. Among the candidates, Ag-CuBi2O4/CNTs/Bi2S3 with a 10% loading of Bi2S3 showed the highest photocatalytic activity. The enhanced performance was attributed to the high surface area, reduced recombination rate of charge carriers, faster separation of photogenerated carriers, and high redox ability. The carbon nanotubes (CNTs) acted as a transfer bridge in the layered structure for electrons. The study provides an economical approach for obtaining a stable semiconductor-based photocatalytic system.