Photocatalytic Degradation of Alizarin Red S by Using a Layered Zn/Al-NO3 Double Hydroxides

This research presents the use of layered Zn-Al-NO3 layered double hydroxides (LDH) which photocatalytically degraded Alizarin Red S (ARS) under a UV source. The prepared photocatalytic material was characterized by employing the use of X-Ray Diffraction (XRD) analysis, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared (FTIR) spectroscopy and Band gap Energy using Tauc plot. The analyzed XRD patterns of Zn-Al-NO3 show characterized diffraction angles typical of LDH. Also, the XRD patterns were used to calculate the apparent crystallite size (32.5 nm). The bandgap energy of the LDH was determined to be 3.2 eV. The effect of the initial concentration of the ARS dye, catalyst amount or dose and pH were also determined. The Zn-Al-NO3 efficiently degraded ARS at (69.91%), which could be attributed to its smaller crystallite size. The kinetic study (reaction rate and half-life) of the photodegradation appeared to be R 2 = 0.9886 and (t1/2) = 76.7 min, the data fit the Langmuir Hinshelwood expression, which follows the pseudo-first-order kinetic model.