Synthesis and optical properties of Au decorated colloidal tungsten oxide nanoparticles

Tahmasebi, Nemat; Mahdavi, Seyed Mohammad

doi:10.1016/j.apsusc.2015.07.181

Cited by 13 publications

(2 citation statements)

References 45 publications

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“…The Au element is detected at 83.97 and 87. 64 eV, values which are in accordance with the 4f 7/2 and 4f 5/2 energy levels of gold in the metallic state (Au 0 ), respectively [56]. This confirms, for both composite samples, the presence of gold on the one hand and, on the other hand, the good reduction of Au 3+ ions by NaBH 4 to metallic gold.…”

Section: Structural and Microstructural Characterization Of Au/wo 3 C...supporting

confidence: 84%

Plasmonic Photocatalysts Based on Au Nanoparticles and WO3 for Visible Light-Induced Photocatalytic Activity

Desseigne,

Chevallier,

Madigou

et al. 2023

Catalysts

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In this work, we report the application of Au/WO3 composite as a photocatalyst for the degradation of dyes under solar light irradiation. Au/WO3 nanocomposites were synthesized using an acid precipitation method followed by an impregnation/reduction at room temperature. Two composites were obtained by loading gold nanoparticles on two morphologies of nanostructured WO3, nanoplatelets (NP), and pseudospheres (PS). The elaboration parameters of the nanocomposites were optimized according to the gold mass percentage, the HAuCl4 precursor concentration, and the impregnation time. The structural, microstructural, and textural characterization were conducted using advanced techniques: XRD, SEM/TEM microscopies, and XPS and DRS spectroscopies. The optimal synthesis parameters are a 48 h impregnation of a five mass percentage of gold from a HAuCl4 precursor with a concentration of 10−3 mol·L−1. The obtained composites were formed with Au nanoparticles of 7 nm in size. The XRD analyses did not reveal any modification of the oxide supports structure after gold grafting, contrary to the sorption analyses, which evidenced a change in the state of the materials surface. XPS analysis revealed the reduction of W6+ ions into W5+, favoring the presence of oxygen vacancies. Furthermore, a localized surface plasmon resonance effect was observed in the composite at 540 nm. The photocatalysis results of several dye pollutants have shown a selective degradation efficiency depending on the charge of the polluting molecules, pH medium, and mass loading of the catalysts. At the native pH, the photocatalysis process is highly efficient on a cationic molecule, with a low adsorption capacity. Au/WO3 PS composite appears to be the most efficient, degrading almost the whole RhB and MB only in 60 min and 90 min, respectively, while, for the MO anionic dye, the degradation is more efficient in acidic medium (80%) than in basic medium (0%). Trap tests of the main active species were investigated and a photodecomposition mechanism is proposed.

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