Efficient removal of antibiotic linezolid over Pd nanoparticles/polypyrrole-carbon black/Bi2S3 visible light photocatalyst

Abstract

The severe contamination of natural water has posed a significant threat to regulatory authorities and scientific communities. Herein, we focus on developing a highly efficient ternary photocatalyst of Bi2S3 nanostructure, polypyrrole doped carbon black (PPC), and palladium nanoparticles (Pd NPs) for detoxification of contaminated water. The ternary photocatalyst, comprised of Pd NPs, PPC, and Bi2S3, was synthesized through a combination of hydrothermal approach, ultrasonication, and photoreduction methods. X-ray diffraction (XRD) analysis confirmed the orthorhombic phase of Bi2S3, while the formation of the ternary photocatalyst was verified using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Transmission electron microscopy (TEM) revealed the presence of Pd NPs (5–15 nm), compact beads/cocoons like structure of PPC, and rod and spherical irregular particles of Bi2S3. Diffuse reflectance spectroscopy (DRS) indicated a reduction in the band gap energy of the Pd@PPC/Bi2S3 photocatalyst. The newly developed Pd@PPC/Bi2S3 ternary photocatalyst exhibited remarkable efficiency in removing the colorless antibiotic drug linezolid (LZD) and the methylene blue (MB) dye under visible light exposure. The ternary framework demonstrated exceptional photodegradation activity, eliminating 93.05 % of LZD in just 40 min, which was approximately 225 % more effective than bare Bi2S3. Additionally, the Pd@PPC/Bi2S3 nanostructure efficiently eliminated MB, completely degrading the dye molecule in only 18 min. The enhanced photocatalytic activity of Pd@PPC/Bi2S3 could be attributed to the increased surface area, improved light absorption, and efficient separation and rapid migration of charge carriers, as evidenced by photoluminescence and photocurrent transient studies.