Interface engineering of a magnetic 2D-C3N4/Fe2O3/NiFe-LDH heterostructure for efficient photocatalytic degradation of methylene blue and rhodamine B dyes under visible light

Double layer hydroxide (LDH) as a photocatalyst has potential features in water pollution control. In the present study, the iron (III) oxide /two-dimensional carbon nitride/nickel‑iron LDH (Fe 2 O 3 /2D-C 3 N 4 /NiFe-LDH) composite was synthesized by pyrolysis and co-precipitation process from waste iron rusts as one of the cheap precursors along with NiFe-LDH and g-C 3 N 4. The photocatalytic activities of magnetic Fe 2 O 3 /2D-C 3 N 4 /NiFe-LDH as stable photocatalyst for degradation of methylene blue (MB) and rhodamine B (RhB) as cationic dyes was studied and then the characteristics of the resulting materials, including morphology, structure, crystal phase, optical and electronic properties, were clearly investigated using different techniques. The fabricated Fe 2 O 3 /2D-C 3 N 4 /NiFe-LDH provide greatly improved photocatalytic performance for dye degradation compared to the sole Fe 2 O 3 and Fe 2 O 3 /g-C 3 N 4.The maximum elimination efficiency of MB and RhB are 91.2% and 88.5% respectively. 80% COD photodegradation was achieved under optimal conditions including catalyst loading (0.36 g/L), initial pH (9.0), LED irradiation time (60 min), and initial concentration of MB (10 mg/L) and RhB (9 mg/L). The obtained photocatalyst was effectively recovered using an applied magnetic field. Based on the reusability study, the fabricated photocatalyst was chemically stable and corrosion resistant.