Photo-degradation of basic green 1 and basic red 46 dyes in their binary solution by La 2 O 3 -Al 2 O 3 nanocomposite using first-order derivative spectra and experimental design methodology.

In this work, the lanthanum oxide-aluminum oxide (La2 O3 -Al2 O3 ) nanocomposite is introduced as an efficient photocatalyst for the photo-degradation of the dyes basic green 1 (BG1) and basic red 46 (BR46) in their binary aqueous solution under the UV light irradiation. The properties of this catalyst are determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), and UV-visible spectrophotometry. The first-order derivative spectra are used for the simultaneous analysis of the dyes in their binary solution. The screening investigations indicate that five parameters including the catalyst dosage, concentration of the dyes, irradiation time, and solution pH have significant effects on the photo-degradation of the dyes. The effects of these variables together with their interactions in the photo-degradation of the dyes are studied using the Box-Behnken design (BBD). Under the optimum experimental conditions, obtained via the desirability function, the photo-catalytic activities of La2 O3 -Al2 O3 and pure Al2 O3 are also investigated. The results obtained show an enhancement in the photo-catalytic activity when La2 O3 nanoparticles are loaded on the surface of Al2 O3 nanoparticles.