High-efficient photocatalytic degradation of commercial drugs for pharmaceutical wastewater treatment prospects: A case study of Ag/g-C3N4/ZnO nanocomposite materials.

Pharmaceutical drugs' removal from wastewater by photocatalytic oxidation process is considered as an attractive approach and environmentally friendly solution. This report aims to appraise the practical application potential of Ag/g-C3N4/ZnO nanorods toward the wastewater treatment of the pharmaceutical industry. The catalysts are synthesized by straightforward and environmentally-friendly strategies. Specifically, g-C3N4/ZnO nanorods heterostructure is constructed by a simple self-assembly method, and then Ag nanoparticles are decorated on g-C3N4/ZnO nanorods by a photoreduction route. The results show that three commercial drugs (paracetamol, amoxicillin, and cefalexin) with high concentration (40 mg L-1) are significantly degraded in the existence of a small dosage of Ag/g-C3N4/ZnO nanorods (0.08 g L-1). The Ag/g-C3N4/ZnO nanorods photocatalyst exhibits degradation performance of paracetamol higher 3.8, 1.8, 1.3 times than pristine g-C3N4, ZnO nanorods, and g-C3N4/ZnO nanorods. Furthermore, Ag/g-C3N4/ZnO nanorods have an excellent reusability and a chemical stability that achieved paracetamol degradation efficiency of 78% and remained chemical structure of the photocatalyst after five cycles. In addition, the photocatalytic mechanism explanation and comparison of photocatalytic drugs' degradation ability have also been discussed in this study.

An improved green synthesis method and Escherichia coli antibacterial activity of silver nanoparticles.

Silver nanoparticles (Ag NPs) were synthesized by an improved green synthesis method via a photo-reduction process using low-power UV light in the presence of poly (vinyl pyrrolidone) (PVP) as the surface stabilizer. The effective synthesis process was achieved by optimized synthesis parameters such as C2H5OH: H2O ratio, AgNO3: PVP ratio, pH value, and reducing time. The formation of Ag NPs was identified by Ultraviolet-visible (UV-vis) absorption spectra, X-ray diffraction pattern (XRD) and Fourier transform infrared spectroscopy (FTIR) spectra. Ag NPs were crystallized according to (111), (200), and (220) planes of the face-centered cubic. The transmission electron microscopy (TEM) image showed that the morphology of Ag NPs was uniform spherical with the average particle size of 16 ±â€¯2 nm. The results of XRD pattern, TEM image, and dynamic light scattering (DLS) analysis proved that Ag crystals with uniform size were formed after the reduction process. The mechanism of the formation of Ag NPs was proposed and confirmed by FTIR spectra. The antibacterial activity of Ag NPs against Escherichia coli (E. coli) was tested and approximately 100% of E. coli was eliminated by Ag NPs 35 ppm. In the future, this study can become a new process for the application of Ag NPs as an antibiotic in the industrial scale.