Nanoparticles of ZnS doped with iron as photocatalyst under UV and sunlight irradiation

Abstract

AbstractNanoparticles of zinc sulfide doped with iron were synthesized by controlled co-precipitation and used as a photocatalyst in the photodegradation of congo red as color pollutant. The photoreactivity of doped zinc sulfide was studied with varying mole fraction of Fe3+ to zinc ion, pH of solution, dosage of photocatalyst and concentration of dye. The characterization of nanoparticles was done using ultraviolet– visible spectra, X-ray diffraction pattern and scanning electron microscopy and transmission electron microscopy images. The size range of nanoparticles was determined to be 10–40 nm. In the presence of 0.8 g/L of ZnS:Fe (0.5%) nanophotocatalyst, 12.0 mg/L of congo red and pH 6, the degradation efficiency was 92% under UV and 98% under sunlight irradiations in the time of 120 min and 12 h, respectively. The pseudo-first order rate constant kinetic was obtained 2.12 × 10−2 min−1 and 2.9 × 10−2 h−1 under UV and sunlight irradiation. The reproducibility of photoreactivity of the proposed photocatalyst was 92–90%degradation in four cycles of photodegradation.