Fotocatalisadores Heterogêneos Avançados Baseados em Nióbio para Remediação Sustentável de Sulfeto Inorgânico

Resumo

This study addresses the issue of inorganic sulfide, a corrosive and highly toxic substance widely
found in industrial effluents, causing significant economic and environmental damage. We present a
compelling, economically advantageous, and environmentally sustainable alternative to conventional
approaches for removing this pollutant through heterogeneous photocatalysis with visible light
irradiation. Three new photomaterials were developed through chemical modifications with cobalt
species and coupling the coloured molecule methylene blue as a photosensitizer to the semiconductorbased
Nb₂O₅. The synthesized photocatalysts exhibit remarkable energy absorption capabilities in the
2.1 and 2.6 eV range. Among them, the Nb^(V)OCoO material deserves special attention for its ability
to almost wholly photo-oxidize the target pollutant with a half-life time of 32 minutes, complying with
stringent U.S. environmental standards of only 30 ppm remaining of HS^- and S^2-. Furthermore, this
material demonstrates robustness by maintaining over 80% of its activity after five reuse cycles and
significantly reducing the solution’s toxicity, producing fewer toxic species, such as SO₃^2- and SO₄^2-.
This study offers a practical and sustainable solution for inorganic sulfide removal, representing notable
advancements in environmental and industrial management, confirming the feasibility and potential of
these photocatalysts as a promising alternative.