H2O2-assisted metallic Bi-loaded Bi2Sn2O7 for efficient photocatalytic marine bacteria removal

Abstract

The notorious issue of hazardous growth in ballast water and its potential for widespread diffusion pose significant challenges to the sustainable development of maritime transportation economies. Here, a simplified and sustainable method is presented for synthesizing metallic Bi-doped Bi₂Sn₂O₇, assisted by H₂O₂ to construct a Fenton-like system for the photocatalytic inactivation of marine bacteria. The introduction of metallic Bi is beneficial to the overall sterilization improvement, notably, the 3BBSO (Bi/Bi₂Sn₂O₇) exhibits optimal selectivity in marine bacteria inactivation, with improved decomposition of H₂O₂. The combination of metallic Bi and additional H₂O₂ contributes to the separation of photo-generated charges and the production of •OH radicals, thereby enhancing sterilization efficiency in natural seawater. Furthermore, characterization results demonstrate that the metallic Bi act as a pivotal active sites for the enrichment of free electrons and adsorption centers for •OH, increasing the light absorption range and promoting photocatalytic bacterial inactivation. DFT simulations suggest that metallic Bi provides an optimal position for H₂O₂ abundance, utilizing aggregated electrons to generate more •OH radicals. This sustainable framework offers valuable insights into the treatment of ballast water by deactivating the concentration of marine microorganisms.