Synthesis and characterization of iron sulfide immobilized on Algerian halloysite clay (HKDD3) with enhanced removal of methylene blue from aqueous medium

The aim of this study is to functionalize an Algerian halloysite clay (kaolin Djebel Debbagh, HKDD3) with FeS nanoparticles by employing a hydrothermal approach and exploring its ability to remove methylene blue under visible light irradiation. The FeS-HKDD3 photocatalyst was synthesized successfully and exhibited good crystallinity. Different techniques were used to characterize the produced photocatalyst, including XRD, STEM/EDS, TEM, BET, and UV–vis DRS in order to investigate its structure, morphology, and optical performance. The HKDD3 is a natural halloysite having a tubular shape with a length ranging from 500 nm to several micrometers and a diameter that is estimated from 50 to 100 nm. The iron sulfide nanoparticles are immobilized as cube aggregates on the surface of the halloysite. The visible range displayed a strong absorption of the obtained photocatalyst, with an estimated bandgap of 1.60 eV, according to UV–vis DRS findings. The results exhibited a higher efficiency toward synergic adsorption-photocatalytic degradation effect for methylene blue dye removal.