New polyvinyl alcohol/carbon quantum dots (PVA/CQDs) nanocomposite films: Structural, optical and catalysis properties

Abstract In this literature, new PVA/CQDs nano-composites films were made-up via solution casting approach for the methylene blue dye removal from wastewater. PVA/CQDs nano-composite films were achieved by the marriage of PVA and the CQDs nano-particles, after the preparation of zero-dimension CQDs nano-particles by microwave heating process. The characterization and the optical properties of PVA/CQDs nano-composite films were reported by using X-ray diffraction (XRD), the Fourier Transformation Infrared Spectroscopy (FTIR) and the Uv–vis spectrophotometer. The application of (PVA/CQDs) nano-composite to remove the wastewater dye was performed. The XRD patterns and FTIR spectra confirmed that the strong interaction between PVA polymer and CQDs nano-particles via hydrogen bonding. The tunable structure and optical properties of PVA/CQDs nano-composite are attributed to the concentrations of CQDs nano-particles embedded in PVA matrix. The experiments of the adsorption process, at room temperature, showed that (PVA/CQDs 2 wt.%) nano-composites have the ability to eliminate a large concentration of the methylene blue dye (30 mg/L) from aqueous solution with removal efficiency about 97 ± 1% after 40 min. In addition, the adsorption behavior submitted to the linear model of Freundlich isotherm and non-linear pseudo-first-order model. Also, PVA/CQDs can be reused five times after regeneration without any loss of their efficiency (removal ≈97 ± 1%). Finally, PVA/CQDs nano-composite films are expected to find applications in anti-ultraviolet, catalytic water decomposition and desalination.