ZnO/Au Hybrid Nanoarchitectures: Wet-Chemical Synthesis and Structurally Enhanced Photocatalytic Performance

Abstract

A facile method is introduced to prepare large-area gold-coated ZnO nanorods, featuring the capability to tailor both the spatial distribution and the concentration of metal nanocrystals. The Au nanoparticles-loaded ZnO nanorods exhibit complete catalysis-degradation Rhodamine B within 15 min, which substantially surpass other TiO(2)- and ZnO-based photocatalysts. Furthermore, The ZnO/Au nanocomposites can removal about 91% of environmental persistent 4-chlorophenol from water after 300 min irradiation. The better photocatalytic performance is attributed to the one-dimentional structure of high-quality ZnO nanorods and the large-area noble metal decoration. These promising results would make this photocatalyst an exceptional choice for the environmental purification of organic pollutants in aqueous solution. This approach may also give rise to a new class of multifunctional materials with possible applications in energy-conversion devices, biofunctionalized materials, and infrared-emitting/detecting devices.

Hybrid materials of ZnO nanostructures with reduced graphene oxide and gold nanoparticles: enhanced photodegradation rates in relation to their composition and morphology

“…Solution phase deposition. rGO-ZnO was prepared by the addition of 300 mmoles of Zn(acac) 2 and 600 mmoles of ammonia to rGO dispersion (in 25 mL of ethanol) in a roundbottom flask followed by heating in an oil bath maintained at 120 1C for 8 h. The product was filtered, washed and dried. For the synthesis of rGO-Au-ZnO, rGO-Au dispersion was used instead of rGO in the above process.…”

“…rGO-ZnO was prepared by adding 300 mmoles of Zn(acac) 2 and 600 mmoles of ammonia to rGO dispersion (in 20 mL of ethanol) in a Teflon lined stainless steel autoclave (pressure vessel) followed by heating in an oven at 120 1C for 8 h. After completion of the reaction, the autoclave was cooled down to room temperature. The product was collected and washed with Milli-Q water.…”

“…Hence, there has been renewed interest in improving the efficiency of ZnO by introducing defect levels or charge transfer states to suppress the recombination effects. 2,3 The defect engineering in the parent ZnO material in the form of oxygen and zinc vacancies or interstitials as trap states is shown to promote charge separation. 3,4 Combining ZnO nanostructures with noble metal nanoparticles and carbon nanostructures provides alternate charge transfer pathways prolonging the lifetime of electrons and holes.…”

“…3,4 Combining ZnO nanostructures with noble metal nanoparticles and carbon nanostructures provides alternate charge transfer pathways prolonging the lifetime of electrons and holes. 2,5 Thus, Au-ZnO hybrid nanoarchitectures and Ag-ZnO heterostructures are found to be efficient photocatalysts than the ZnO constituent alone. [6][7][8][9][10][11] Photoluminescence studies and Kelvin probe microscopy uphold facile photoelectron transfer from ZnO to metal.…”

Photocatalytic Activity and Selectivity of ZnO Materials in the Decomposition of Organic Compounds

“…[2,3] The hybridization of ZnO materials with conventional dopants or nanoparticles has been considered as a feasible method of modifying its electronic structure and properties. [4][5][6][7][8] Specifically, efforts have been devoted to achieving p-type ZnO through elemental doping. [9] However, the synthesis of p-type ZnO remains challenging if alkali metals, such as Li and Na, are used as dopants, because the interstitial sites in wurtzite ZnO are more favorable for alkali ions, owing to their small ionic sizes, thus resulting in n-type semiconductive ZnO.…”