Electrochemical strategy for grown ZnO nanoparticles deposited onto HY zeolite with enhanced photodecolorization of methylene blue: Effect of the formation of Si O Zn bonds

Nanoparticles of electrogenerated zinc-supported HY zeolite (EGZnO/HY) catalyst were prepared by a simple electrochemical method. The interaction between zinc species and HY support during the electrolysis was found to affect the EGZnO/HY structure. In addition to the formation of EGZnO nanoparticles (<30 nm in size) that distributed on the surface of HY support, an isomorphous substitution of Al with Zn also occurred in the aluminosilicate framework to result in a Si O Zn bonds. The photoactivity of EGZnO/HY was tested on the decolorization of methylene blue (MB). An amount of 0.375 g L−1 of 1 wt% EGZnO/HY was found to be the optimum dosage for 10 mg L−1 MB, which resulted in 80% of maximum decolorization after 6 h of contact time at pH 3 under fluorescent light (420 nm). Increasing the EGZnO loading led to additional formation of Si O Zn bonds and lessened the number of EGZnO nanoparticles, which then reduced the photodecolorization percentage of MB.The photocatalytic reaction was follows the first-order Langmuir–Hinshelwood model, and gives partially mineralization. The photocatalyst was still stable after five cycling runs with no Zn leaching

Cymbopogon nardus Mediated Synthesis of Ag Nanoparticles for the Photocatalytic Degradation of 2,4-Dicholorophenoxyacetic Acid

Advanced extraction method such as simultaneous ultrasonic–hydrodistillation (UAE–HD) extraction method has been proved to increased extraction yield of plant material yet the application of this method in the preparation of metal nanoparticles has not been studied. In this study, Cymbopogon nardus (C.N) extracted via UAE-HD extraction method was used to synthesis silver (Ag) nanoparticles. XRD and TEM analysis confirms the formation of spherical shape Ag nanoparticles with size ranging between 10-50 nm. FTIR spectra suggest the presence of bioactive compounds in the C.N leaves extract that may responsible to the stabilization and reduction of Ag ions (Ag+) to metallic Ag nanoparticles (Ag0). The TPC analysis successfully proved that huge number of phenolic compound greatly involved in the nanoparticles synthesis process. Next, the catalytic activity of the synthesized Ag nanoparticles was tested towards the degradation of 2,4-Dicholorophenoxyacetic acid herbicide with remarkable degradation performance up to 98%. Kinetic study confirms that surface reaction was the controlling step of the catalytic process. Copyright © 2019 BCREC Group. All rights reserve