Bismuth-based nanocomposites as potential materials for indoor air treatment

Air pollution is a worldwide health hazard; thus, improving air quality is a demanding need. Photocatalysis is a robust strategy for air treatment. The boosted activity of the photocatalytic system depends on tuning their properties for the particular application. BiOX (X: Cl, I) compounds are emergent photocatalytic systems with numerous advantages for air treatment. However, their optical properties (E_g) and fast recombination of active species (e^-/h⁺) limit their practical applications. In this study, we remark on the properties of BiOX-GO systems for indoor air purification. We use a microwave-activated solvothermal technique to synthesize the nanomaterials (NMs). BiOX NMs exhibit hierarchical 3D structures, crystallinity, and tunable optical absorption properties. BiOX-GO composites present an enhanced visible-light photocatalytic activity due to the electron acceptor capacity of GO and modification of E_g. The indoor air disinfection capacity of the NMs ranked as follows: BiOCl-GO (96.7%) > BiOI-GO (96.2%) > BiOI (89.2%) > BiOCl (79%). The higher efficiency under visible light of BiOCl-GO can be related to the presence of oxygen vacancies, strong oxidation potential, and single crystalline phase of the materials. Due to the abundance and biocompatibility of bismuth-containing compounds, together with their enhanced visible light activity, BiOX become potent candidates for environmentally sustainable remediation technologies.