Surface Engineering of CdS Quantum Dots for Photocatalytic Applications under Direct Sunlight

Comparative Study on the Influence of Noble Metal Nanoparticles (Ag, Au, Pd) on the Photocatalytic Activity of ZnO NPs Embedded in Renewable Castor Oil Polymer Matrices

Hybrid polymeric materials, due to the unique combination of properties that can be obtained by the convenient variation of organic and inorganic components, represent an attractive alternative for many applications, especially photocatalysis. Herein, we report the preparation of nanocomposite films containing functionalized ZnO nanoparticles, as well as in situ photogenerated noble metal nanoparticles (Ag, Au, Pd), for the achieving of materials with enhanced photocatalytic activity under visible light. The flexible free-standing nanocomposite films were synthesized by photopolymerization of a monomer mixture (silane castor oil urethane dimethacrylate and polypropylene oxide urethane dimethacrylate) in the presence of a Irgacure 819 photoinitiator. The efficiency of ZnO NPs functionalization was established by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis, while the polymer composites were characterized by UV-Vis spectroscopy, X-ray diffraction, transmission electron microscopy and scanning electron microscopy to evidence the formation, size and distribution of the nanoparticles inside the photocrosslinked matrix. To establish the photocatalytic capacity of nanocomposite films, the decomposition of various pollutants (methyl orange, phenol, metronidazole) was monitored under visible light irradiation, the best results being obtained for Au/ZnO film. Also, the advantage of immobilizing the catalysts in a polymeric support and its recycling ability without a significant decrease in photocatalytic efficiency was analysed.

Real-time monitored photocatalytic activity and electrochemical performance of an rGO/Pt nanocomposite synthesized via a green approach

Herein, we have reported the real-time photodegradation of methylene blue (MB), an organic pollutant, in the presence of sunlight at an ambient temperature using a platinum-decorated reduced graphene oxide (rGO/Pt) nanocomposite. The photocatalyst was prepared via a simple, one-pot and green approach with the simultaneous reduction of GO and Pt using aqueous honey as a reducing agent. Moreover, the honey not only simultaneously reduced Pt ions and GO but also played a key role in the growth and dispersion of Pt nanoparticles on the surface of rGO. Various rGO/Pt nanocomposites with different percentages of Pt nanoparticles loaded on rGO were obtained by tuning the concentration of the Pt source. The high percentage of Pt nanoparticles with an average size of 2.5 nm dispersed on rGO has shown excellent electrochemical performance. The photocatalytic activity of the rGO/Pt composite was enhanced by increasing the weight percent of the Pt particles on rGO, which led to the formation of a highly efficient photocatalyst. The optimized photocatalyst exhibited remarkable photocatalytic activity and degraded 98% MB in 180 minutes; thus, it can be used for industrial and environmental applications.