Catalytic Activity of Gold and Silver Nanoparticles Supported on Zinc Oxide

Abstract

Gold (AuNPs) and silver (AgNPs) nanoparticles have been prepared by “one-pot” synthetic method in the presence of poly(N-vinylpyrrolidone) (PVP). Absorption spectra, size, morphology, and structure of AuNPs and AgNPs were studied by UV-Vis spectroscopy, DLS, SEM, and TEM. According to DLS measurements the average sizes of metal nanoparticles stabilized by PVP in aqueous solution are varied from 10 to 25 nm for AuNPs and from 6.5 to 44 nm for AgNPs. The impregnation method is used to support AuNPs and AgNPs on the surface of ZnO. The amount of AuNPs and AgNPs immobilized on the surface of ZnO does not exceed 0.2 wt.%. The catalytic activity of AuNPs and AgNPs supported on the surface of ZnO was evaluated with respect to decomposition of hydrogen peroxide. The optimal conditions for H2O2 decomposition were found to be dependent on of the amount of the catalyst, concentration of substrate, molecular weight of PVP, and temperature. The activation energy of H2O2 decomposition is equal to 44.1 kJ×mol-1. The decomposition of H2O2 in the presence of AuNPs and AgNPs supported on ZnO surface is discussed in the context of supramolecular catalysis mimicking catalase-like behavior. The recyclability of AuNPs supported on ZnO surface was tested.

Catalytic Properties of Polyvanadate Xerogels Supported to Anatase in Decomposition of Hydrogen Peroxide and Oxidation of o‐Xylene

“…Decomposition of H 2 O 2 was carried out in thermostated glass reactor equipped by magnetic stirrer . Thin powders of PV 7 /TiO 2 and PV 50 /TiO 2 were dispersed in 0.9 mL aqueous solution of H 2 O 2 and the volume of released oxygen was measured by burette at definite time interval.…”

“…Both decomposition of hydrogen peroxide and oxidation of oxylene in the presence of catalysts were carried out in a glass reactor described in. [15] The X-ray diffractometer (PANanalytical, X'Pert Pro) was used for identification of TiO 2 and catalyst phases and determination of their average crystal size. The XRD data were interpreted on the basis of Bragg's equation.…”

“…Transmission electron microscope (TEM) measurements were carried out on JEM‐1011 (JEOL, Japan). Both decomposition of hydrogen peroxide and oxidation of o‐xylene in the presence of catalysts were carried out in a glass reactor described in . The X‐ray diffractometer (PANanalytical, X'Pert Pro) was used for identification of TiO 2 and catalyst phases and determination of their average crystal size.…”

“…[15] Thin powders of PV 7 /TiO 2 and PV 50 /TiO 2 were dispersed in 0.9 mL aqueous solution of H 2 O 2 and the volume of released oxygen was measured by burette at definite time interval. The temperature of reaction is 338 K, the mass of catalyst is 30 mg and the concentration of H 2 O 2 is 37%.…”

Poly(n‐vinylpyrrolidone) Protected Gold and Silver Nanoparticles: Synthesis, Characterization and Catalytic Properties

“…It was found that polymer‐protected AuNPs convert 4‐nitrophenol to 4‐aminophenol with high yield (97‐99% conversion). The catalytic activity of PVP‐AuNPs supported on the surface of aluminum oxide was evaluated with respect to decomposition of hydrogen peroxide …”