Lead Sulphide Nanoparticles as Photocatalyst for the Degradation of Methylene Blue: Effects of pH, Time, Adsorption Kinetics and Recyclability Studies

Abstract

We report the synthesis and morphological studies of lead sulphide nanoparticles prepared from lead(II) complexes of morpholine dithiocarbamate (PbS1), thiomorpholine dithiocarbamate (PbS2), and N-(2-hydroxyethyl)phenyl dithiocarbamate (PbS3). Powder X-ray diffraction patterns (p-XRD) of the PbS nanoparticles are indexed to face-centered cubic phase of PbS. High-resolution transmission electron microscopy (HRTEM) micrograph revealed quasi-spherical PbS nanoparticles with particle size in the range 13.86–36.06 nm while scanning electron microscopy (SEM) revealed flaky/spherical/rough surface morphology. Photocatalytic degradation of methylene blue dye by the PbS nanoparticles showed degradation efficiency of 72.6 % for PbS1, 75.9 % for PbS2, and 47.4 % for PbS3. The photodegradation efficiency shows a correlation between efficiency and morphological properties. Total organic content removal by PbS2 is 69.5 % while that of PbS1 is 64.2 % and PbS3 is 40.1 %. The as-prepared PbS nanoparticles exhibited remarkable photostability in the recyclability studies.