Photocatalytic activity of a nitrogen-doped TiO2 modified zeolite in the degradation of Reactive Yellow 125 azo dye

In this study, the hybrid material based on natural zeolite modified with nitrogen-doped TiO2 photocatalyst (Z-TiO2-N) was synthesized by solid-state reaction under microwave-assisted hydrothermal conditions. The surface characterization of hybrid material has been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy dispersive X-ray (EDX) analysis, and FT-IR spectroscopy. The photocatalytic activity of Z-TiO2-N photocatalyst under UV and VIS irradiation was determined for the degradation of Reactive Yellow 125 (RY 125) dye solution. Also, UV–VIS diffuse reflectance (DRUV–VIS) spectroscopy was used to determine the light absorption properties of the hybrid material. The operational conditions using photocatalyst dose of 1 g/L at pH 3 were established as optimal conditions for photocatalytic application in RY 125 dye solution degradation. The experimental studies revealed that the degradation efficiency expressed in terms of discoloration, aromatic ring-opening and mineralization depended strongly on the initial RY 125 dye solution concentrations. The photocatalyst exhibited a good performance for discoloration and aromatic-ring opening processes at all studied concentrations (25, 50 and 100 mg/L) but an effective mineralization was reached only for 25 mg/L RY 125 dye solution. Also, the degradation of low concentrations of RY 125 dye solution was achieved using Z-TiO2-N catalyst under VIS irradiation.

► We synthesized nitrogen-doped TiO2-modified zeolite. ► We used a new solid-state reaction under microwave-assisted hydrothermal conditions. ► We proved the photocatalytic activity especial under visible irradiation. ► The mineralization degree of the Reactive Yellow 125 azo dye was examined.