Facile Hydrothermal Synthesis of SWCNT/PbS Nanocomposite as High-Performance Photocatalysts for Organic Pollutant Degradation

A novel synthetic strategy for SWCNT/PbS nanocomposite has been developed. A SWCNT/PbS nanocomposite was prominently synthesized with a large band gap via a surfactant-assisted hydrothermal route with an average size of 27.44 nm. A perfectly oriented and well-dispersed PbS nanoparticles were prepared (in situ) using a mixture of cetyl tri-methyl ammonium bromide (CTAB) and ethylene diamine tetra acetic acid (EDTA), as a stabilizer and dispersant, respectively. FTIR, FESEM, TEM, and Raman analysis thoroughly examined the nanocomposite. Furthermore, the photocatalytic activity (96.32%) has been demonstrated by employing methylene blue (5 ppm) under UV-visible light irradiation, which is one of the potential applications of the wide band gap SWCNT/PbS nanocomposite. Density Functional Theory (DFT) calculations revealed a progressive increase in the HOMO–LUMO energy gap during degradation, indicating stepwise breakdown of the chromophoric structure. Through SWCNT/PbS nanocomposite, the synergistic role of SWCNTs in facilitating charge transfer through SWCNT/PbS nanocomposite and PbS nanoparticles serving as a highly active UV-visible light absorber accelerates dye mineralization. The observed findings highlighted the potential of SWCNT/PbS nanocomposite as an efficient and sustainable photocatalyst for wastewater treatment applications.