Activated carbon-supported NiS/CoS photocatalyst for degradation of methyl violet (MV) and selective disinfection process for different bacteria under visible light irradiation

Abstract

The activated carbon (AC) supported sulphur-based Ni/Co photocatalysts were prepared using the simple chemical precipitation method. The prepared samples were characterized with advanced scanning electron microscope, x-ray diffraction, Raman, UV-DRS, PL analyses. SEM images presented that AC-supported NiS and CoS nanocomposites were spherical and had rod-like morphologies. To determine photocatalytic performance and the kinetic model, the decomposition of Methyl Violet (MV) was carried out on all the photocatalyst samples. The synergetic effect was performed by comparing NiS/AC, CoS/AC and Ni/CoS/AC composites. The photocatalytic yield of the Ni7Co3/AC nanocomposite sample towards (MV) was found to be 98% in 90 min also under the same experimental conditions other AC-supported samples which CoS/AC, NiS/AC, and Ni3Co7/AC showed 56%, 74% and 78% photodegradation efficiency, respectively. The obtained results showed that the optimal content of component affects the degradation ability and also composites with increased NiS content displaying better photocatalytic performance. Ni7Co3/AC inactivation performance against S. aureus and E. faecalis was outstanding; nearly 100% inactivation was attained in less than 2 h. S. aureus and E. faecalis are both Gram positive (Gr+) bacteria. The Ni7Co3/AC composite deactivated Gr+ bacteria but had no effect against Gr- bacteria during the incubation period.