ZnO AND Ag-ZnO CRYSTALS: SYNTHESIS, CHARACTERIZATION, AND APPLICATION IN HETEROGENEOUS PHOTOCATALYSIS

Abstract

Recebido em 28/07/2015; aceito em 22/12/2015; publicado na web em 11/03/2016ZnO and Ag-ZnO were synthesized in a simple and efficient manner by thermal decomposition of zinc oxalate and silver/zinc mixed oxalate. The influence of the addition of metallic silver on ZnO particles and the effect of temperature in the thermal treatment were investigated. The samples were characterized by thermogravimetric analysis, Raman, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, specific surface area (Brunauer-Emmett-Teller) and diffuse reflectance spectroscopy. The photocatalytic activity of these materials in the decolorization of direct red 23 diazo dye was studied. The complete conversion into oxides from oxalates at lower temperatures was determinant in the photocatalytic efficiency of both the oxides. The presence of silver in zinc oxide, treated at 400 °C, more than doubled the rate constant of diazo dye decolorization (6.87×10-3 min -1) with respect to ZnO, treated at 600 °C, resulting in 3.07×10 -3 min -1 under UV irradiation at 30 °C.

Biogenic ZnO Nanoparticles Synthesized from Origanum vulgare Abrogates Quorum Sensing and Biofilm Formation in Opportunistic Pathogen Chromobacterium violaceum

“…However, biosynthetically prepared NPs are more economical, robust, and environmentally friendly than a synthesis techniques [6]. The ZnO has emerged as a potential candidate to be used in industry as it is nontoxic, has greater photoactivity, is inexpensive, antimicrobial, and biocompatible [7][8][9][10][11], and has innumerable applications in the fields of cosmetics, food preservation, nanomedicines and electrode, biosensor, photocatalyst, and solar cell manufacturing [11,12]. Crystalline morphology and surface area ZnO NPs are used in bioactive applications, such as biosensing, antimicrobial preparations, catalysis, photonics, optoelectronics, and other technological applications [13,14].…”

Desenvolvimento de compósitos ZnC2O4/xerogel de carbono para degradação fotocatalítica de azul de metileno sob radiação solar

“…No que tange a morfologia do material XC-ZnC 2 O 4 , vemos que este é composto de partículas de forma poliedral, de dimensões em torno de 50-100nm. Esse comportamento é derivado do oxalato de zinco, como reportado por LUCILHA et al [21].…”

Caracterización de polvos de Cu y ZnO embebidos en una matriz de SiO2

“…Las partículas finas uniformes de óxido de zinc son uno de los principales materiales multifuncionales debido a su gran número de aplicaciones tecnológicas; sensores de gas, catálisis, cosméticos, conservación de alimentos y nanomedicinas (Lucilha et al 2016). Los materiales fotocatalíticos utilizados para degradar contaminantes orgánicos incluyen TiO2, ZnO, Fe2O3, WO3, MoS2 y CdS.…”

“…Las propiedades de las nanopartículas debido a la relación superficie/volumen y efectos cuánticos, mejoran la eficiencia de la fotocatálisis en remediación ambiental, control de olores y esterilización de superficies (Lucilha et al 2016).…”