Synthesis and characterization of novel Mg(OH)۲/CdS heteronanostructures for sunlight induced degradation of phenolic pollutant

Mg(OH)۲/CdS heteronanostructures have been successfully synthesized by a novel precipitation method and the synthesis involves three steps. The first step involves the synthesis of Mg (OH)۲nanoparticles using homogeneous precipitation method. Then, surface-modifying agent citric acid was used to functionalise Mg (OH)۲. Finally, the cadmium sulfide (CdS) shell was deposited on the surface modified Mg (OH)۲by co-precipitation method. The Mg(OH)۲/CdS heteronanostructures were characterized using X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy. DRS results showed blue shift of CdS band gap absorption with respect to bulk CdS. XPS results showed evidence for the binding energies of Mg(OH)۲, Cd and S. The Mg (OH)۲/CdS heteronanostructures was explored as catalyst for sunlight induced photocatalytic degradation of β- naphthol pollutant. The batch of ۰.۲ mg/ mL of Mg (OH)۲/CdS heteronanostructures maintained at pH ۸.۵ showed maximum photodegradation efficiency (۷۵ ± ۲.۱ %). Higher photocatalytic degradation efficiency for Mg(OH)۲/CdS heteronanostructures could be due to incorporation of CdS and increased reactive oxygen species (ROS) generation. The reusability of the Mg (OH)۲/CdS heteronanostructures was also tested, and they show stability for up to three cycles without loss of efficiency.

Keywords:

Mg(OH)۲/CdS heteronanostructures , β- naphthol pollutant , Photocatalysis