Synthesis and characterization of Zn1−XCuXS and Zn1−XNiXS nanoparticles and their applications as photocatalyst in Congo red degradation

In this work, Zn1−XCuXS and Zn1−XNiXS nanocomposites were synthesized by using a controlled co-precipitation. The nanocomposite materials were characterized by the use of UV–Vis spectra, atomic absorption spectroscopy, X-ray diffraction patterns, transmission electron microscopy image and Brunauer–Emmett–Teller method. For Zn1−XCuXS and Zn1−XNiXS nanoparticles, the X-ray diffraction patterns show the zinc-bland crystal structure. The blue shift in band-gap of ZnS was observed through incorporation of Cu2+ and Ni2+ ions. The Congo red photodegradation was performed to study the photoactivity of prepared nanocomposites under UV–Vis irradiation. The effect of dopant mole fraction, dosage of photocatalyst and pH of samples were considered on the decolorization rate of dye and photoactivity of nanocomposites. The maximum degradation of dye was obtained at pH 5–7. The Zn0.94Ni0.06S and Zn0.90Cu0.10S nanocomposites show the highest photoactivity. The influence of hydrogen peroxide and several anions were studied on the photoactivity of proposed catalysts. Also, the reproducibility of nanoparticles behavior as photocatalyst shows at least a four cycles of photodegradation process.