Nanoparticles of MnFeNiCuBi high entropy alloy as catalyst for Fenton and photo-Fenton decomposition of p-nitrophenol

Abstract

We report here preparation of an equi-atomic high entropy alloy (HEA) where Bi (hexagonal) was used along with Mn, Fe, Ni and Cu. The HEA assumed fcc structure after ball milling for 60 h of the arc melted component which was initially having multiple phases. XRD and TEM studies corroborated the HEA formation. The XPS studies of the milled sample inferred a probable formation of multicomponent oxide shells on the surface, which could generate a band gap of 1.62 eV. Hence, the present material emerged as an efficient catalyst, which could completely decompose, PNP in 60 min for Fenton and 20 min for photo-Fenton processes. When tested for four cycles, the HEA also displayed appreciable stability as a photo-Fenton catalyst. Further, the catalyst's soft ferromagnetic nature (MS = 4.55 emu/g) contributes to its recyclability. Given the associated challenges with conventional Fe catalysts utilized in Fenton and photo-Fenton processes, this work provides an alternative as a promising catalyst for treating PNP-containing wastewater. © 2024 Elsevier B.V.