Synthesis of novel heterojunction ZrS ₂ /CeS ₂ /NiS as an efficient photocatalyst for the degradation of methyl orange dye

In this work, we synthesized a novel heterojunction ZrS2/CeS2/NiS nanocomposite by the hydrothermal method. The formation of the synthesized material was confirmed by XRD, while the functional groups present in the synthesized material were confirmed by M‒S bonds via Fourier transform infrared (FTIR) spectroscopy. The light absorption ability of the synthesized material was confirmed with UV–Visible spectrophotometer, surface characteristics via scanning electron microscopy (SEM) and elemental composition via energy dispersive X-ray spectroscopy (EDX) were determined. The average particle size and band gap of the ZrS2/CeS2/NiS nanocomposite were found to be 29.44 nm and 2.19 eV respectively. The photocatalytic efficiency of the synthesized ZrS2/CeS2/NiS nanocomposite was examined with the degradation of methyl orange dye. The ZrS2/CeS2/NiS nanocomposite performed effectively under illumination with a visible light source of 18 watts. The degradation is optimized by varying the experimental parameters viz. light source, light intensity, dye concentration, catalyst amount and pH. The synthesized ZrS2/CeS2/NiS nanocomposite degraded 99.6% of the methyl orange in 100 min at pH 7. Experiments also showed that the synthesized nanocomposite has pH-dependent photocatalytic efficacy, and thermodynamic parameters were evaluated using Arrhenius plot. The catalytic efficiency was reduced from 99.6 to 92% for the second reuse. Scavenger studies have demonstrated the participation of both superoxide (O2) and hydroxide radicals (.OH) in methyl orange degradation. The synthesized ZrS2/CeS2/NiS nanocomposite is excellent and might be used in a variety of ecological applications as well as wastewater treatment.