Detoxification of wastewater with toxic cyanide substance using TiO₂-based photocatalysts

Industrial, agricultural, and domestic chemicals increasingly pollute the environment, affecting water, air, and soil even at low concentrations. This pollution, especially from waste, is a serious global problem. Using renewable energy like sunlight with photocatalysts offers an environmentally friendly way to remove pollutants. The focus of the innovation is the use of V, Er, and Ce-doped, multilayer mosaic-structured TiO₂ thin films coated on glass substrates with their suitable band gap values to enhance the performance and sustainability of traditional TiO₂ photocatalysts for the effective treatment of cyanide-containing wastewater under sunlight/UV light. In this study, it was aimed to produce V, Er, Ce pure/doped TiO₂ thin coatings on glass substrates with sol–gel technique and photocatalytic degradation of cyanide in wastewater by using these substrates. The structural, microstructural and electrical properties of the produced films were investigated and thin films coated on glass substrates were used as photocatalysts in the photocatalytic degradation of cyanide in wastewater under UV/sun light source. As an innovative approach, laboratory and industrial scale TiO₂, V-TiO₂, Er-TiO₂, and Ce-TiO₂ coatings with the anatase phase on glass substrates exhibit a multilayered mosaic architecture. The coatings’ refractive index, film thickness, and energy bandgap were observed to vary within the ranges of 1.6028–1.6075 nD, 2.408–2.750 μm, and 3.08–3.73 eV, respectively. Notably, a 95 % efficiency was achieved in cyanide degradation from wastewater using these modified TiO₂ films, indicating their significant potential for high-performance photocatalytic applications in environmental remediation. Photocatalytic samples demonstrated effective cyanide degradation over 10 industrial-scale cycles, with efficiency declining due to impurity buildup from real wastewater. Cleaning the surface restored activity, highlighting the material's potential for recyclability. As a result, this innovation offers up to 95 % cyanide removal efficiency, reusability and sustainability through surface cleaning, and applicability at industrial scale.