Rapid photodegradation and detection of zolpidem over β-SnWO4 and α-SnWO4 nanoparticles: optimization and mechanism.

We reported the tin (II) tungstate nanoparticles as the photocatalyst and sensor modifier that were synthesized via chemical precipitation reaction and optimized thru the Taguchi design method. The method predicted the best synthesis conditions that led to smaller particles and desired morphologies. Different techniques were used to characterize the chemical structure, morphology, and purity of the nanoparticles. The photocatalytic behavior of different crystalline forms of the SnWO4 nanoparticles (α and β) was considered by photodegradation of methylene orange and zolpidem under UV light irradiation, while the average size of β-SnWO4 and α-SnWO4 nanoparticles prepared in optimum conditions is about 17 nm and 20 nm, respectively. Efficiencies of degradation of methyl orange and zolpidem on β-SnWO4, in the presence of UV irradiation, were 93% and 98% and in the presence of α-SnWO4 were 73% and 82% after 2100 s, respectively. Voltammetric sensing of zolpidem was designed by modification of carbon paste electrode via β-SnWO4 nanoparticles and investigated for determination of the drug in aqueous solution.