Fabricating FeCrCoZrLa High Entropy Alloy towards Enhanced Photocatalytic Degradation of Methylene Blue Dye

Abstract

Fe₂₀Cr₂₀Co₂₀Zr₂₀La₂₀ (at. %) high entropy alloy (HEA) using mechanical alloy (MA) was synthesized by an equiatomic ratio as a function of milling times (0h, 5h, 10h, 20h, 30h, and 50h). The HEA alloys were characterized with X-ray diffractometer (XRD), scanning electron microscopy (SEM), X-ray Energy-Dispersive Spectroscopy (EDX), transmission electron microscopy (TEM), and Differential thermal analysis (DTA). After 50 hours of grinding, the BCC crystalline phase was formed and the crystallite size and microstrain were calculated at 4.7 nm and 1.95 nm, respectively. TEM image of 50 hours of milled powders also confirms a nanocrystalline structure. Using solar energy, visible light photocatalysis is a promising method for removing environmental pollution. The photocatalytic effect of the synthesized nanostructured alloy on aqueous solutions containing methylene blue (MB) was investigated under xenon light. Photocatalytic degradation of the synthesized sample was evaluated by calculating the absorbance drops of the UV–Vis absorption spectra (methylene blue 664 nm).The degradation of the nanostructured alloy for MB was found as 89.76% after 120 min. This implies that the photocatalytic degradation rate is relatively high, and the obtained alloy has been used in practice for the degradation of methylene blue dye effectively.