Tailoring photocatalytic performance through Fe-doped TiO2/ZnO for effective remediation of organic contaminants
Yalda Davoodi, Mohammad Saleh Shafeeyan
Abstract
The development of highly efficient photocatalysts holds significant promise for addressing contemporary environmental challenges. This study focuses on the synthesis and characterization of a novel photocatalyst, iron-doped TiO2/ZnO particles, created through the sol-gel technique. The incorporation of iron ions into the crystalline structure of TiO2/ZnO aims to enhance the photocatalytic efficiency of TiO2. Varying amounts of iron were introduced into the photocatalyst matrix, followed by calcination at 800° Celsius. Thermal analysis, X-ray diffraction, and scanning electron microscopy were employed to assess the thermal properties, crystal structure, and surface morphology of Fe–TiO2/ZnO. The photocatalytic performance and stability of the synthesized photocatalyst were evaluated based on its ability to degrade methyl orange under visible light irradiation. A statistical response surface methodology based on central composite design was employed to develop a predictive model for color removal (as the dependent variable) considering variations in irradiation intensity, initial color concentration, catalyst concentration, reaction time, and pH (as independent variables). The experimental values of color removal exhibited good agreement with the predicted values from the regression model, indicating the accuracy of this model in predicting the mentioned outcomes. The presented model indicated that, for a sample of methyl orange with an initial concentration of 16.31 ppm, a reaction time of 114.22 minutes under direct irradiation of 20.69 watts, a catalyst concentration of 0.67 g, and a pH of 4.77, the optimal color removal efficiency of 68.24 % was achieved.