Application of synthesizing tri-metallic Zn and Ag co-doped TiO2 nano-photocatalyst by a one-step synthesis technique in treating water pollutants

The present trend in synthesis techniques in the wastewater treatment is altering from the more achievement of a product with the desired properties to methods that are highly effective, economical, and environmentally friendly. In the present work, Zn and Ag co-doped TiO2 tri-metallic nanoparticles are synthesized by the molten salt method, which is applied as an effective nano photocatalyst for the removal of methyl orange from the aqueous media. The effect of dopant content on the de-colorization of the methyl orange solution has been optimized by the response surface methodology. The prepared nanomaterial was characterized by the X-ray diffraction, diffusive reflectance spectroscopy, and scanning electron microscopy (SEM). In the pure and single metal doping TiO2 nanoparticles, only the anatase phase was formed. The silver, anatase, and rutile phase could be observed. The pure titanium sample has a band gap of 3.2 eV. All samples have a band gap below this value. The accumulated spherical shaped particles with relatively the same size are available the pure samples. The SEM images show the co-doping results in the formation of larger particles. The experimental results showed that the prepared nanoparticles have a high photo-degradation tendency to remove methyl orange from the aqueous solution under visible light irradiation. The highest photocatalytic activity of 94.2%, belongs to samples containing 0.38% silver and 0.13% zinc.