Superior photocatalytic performance of mechanosynthesized Bi2O3-Bi2WO6 nanocomposite in wastewater treatment

The heterostructured Bi2O3-Bi2WO6 nanocomposites with superior photocatalytic performance have been synthesized by the mechanical alloying method. Both nanosheet and nanoflower-like morphologies are obtained after different durations of milling. The semiconductor-semiconductor (S-S) heterojunction formation with the NHE (normal hydrogen electrode) scale is revealed from the band positions of Bi2O3 and Bi2WO6. Detailed microstructures of all nanocomposites have been characterized by the Rietveld refinement of XRD patterns and analyzing TEM images.The morphological hierarchy and changes of all samples have been disclosed in FESEM images. The bandgap value and the visible-light-driven (VLD) photocatalytic activity of all samples have been measured from the UV-vis absorbance spectra. The Rhodamine B (RhB) dye degradation performance of the photocatalyst, its reusability, and active radical species involved in the photocatalytic reaction in all nanocomposites are obtained by analyzing UV-vis absorbance spectra.The EDX elemental mapping reveals the stability of the photocatalyst. The photocatalytic performance of all milled samples has been investigated through the degradation of RhB dye in an aqueous solution under solar light in the presence. A significant amount (similar to 87%) of RhB degradation within 240 min has been achieved with the 5h milled Bi2O3-WO3 nanocomposite.

Automated summary

Heterostructured Bi2O3-Bi2WO6 nanocomposites were synthesized via mechanical alloying, showing superior photocatalytic performance. The semiconductor-semiconductor heterojunction formation and band positions were revealed, and detailed microstructures were characterized by XRD and TEM analysis. The photocatalytic activity and stability of the nanocomposites were investigated revealing high Rhodamine B dye degradation efficiency under solar light.