Facile ultrasonic synthesis of novel zinc sulfide/carbon nanotube coaxial nanocables for enhanced photodegradation of methyl orange

Zinc sulfide (ZnS) has been widely studied due to its versatile application in photocatalysis. A facile, one-pot, ultrasonic-assisted approach was developed to synthesize coaxial nanocables consisting of highly conductive multi-walled carbon nanotube (CNT) cores and well-crystalline ZnS sheaths. The morphology and structural features of the materials were characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis. The photoluminescence and optical properties of the CNT/ZnS coaxial nanocables are characterized by photoluminescent spectrum and UV–Vis spectroscopy. Methyl orange (MO) dye was chosen as a model for organic pollutants and was used to evaluate the photocatalytic performance of the CNT/ZnS nanocables. CNT/ZnS showed significant visible-light activity in the degradation of MO. Compared with the ZnS powders, the novel CNT/ZnS coaxial nanocables exhibited much higher performance as a photocatalyst. The enhanced performance arises from the structural advantages of the nanocables. First, the CNT cores effectively improved the electronic conductivity of the hybrid materials. Second, the CNT coaxial nanocables had rich hierarchical pores of ZnS sheath and large surface area.