In situ formation of SnO2 nanoparticles on cellulose acetate fibrous membranes for the photocatalytic degradation of organic dyes

We present the development of a novel and green porous nanocomposite for photocatalytic applications, i.e. SnO2/cellulose acetate fibrous mats. The electrospinning method is adopted to form cellulose acetate/tin salt fibrous nanocomposite membranes, followed by a thermally activated conversion of the salt into SnO2 nanoparticles (NPs), directly in the solid fibrous matrix. Detailed microscopic investigations show that the porous composite membranes are composed by defect-free fibers (mean diameter 1.09 ± 0.35 μm) and SnO2 NPs (mean diameter 16.3 ± 3.4 nm), homogenously distributed in the whole volume and on the surface of the polymer fibers. The NPs act as oxidation sites under UV light irradiation, and, under the specific experimental conditions of this study, the total photodegradation efficiency is higher than 90 % for both anionic (methylene blue, MB) and cationic (methyl orange, MO) dyes. Data show that 54 % and 79 % of the MO and MB are mineralized, respectively, the rest being products of demethylation and hydroxylation processes. This novel in situ approach for the formation of pure SnO2 NPs directly in the polymeric fibers by using innocuous solvents, a polymer and a precursor agent with nontoxic byproducts, opens up the possibility to use solid SnO2-based polymer porous composites as efficient materials for water remediation of organic pollutants.