Facile one-pot green synthesis of Au–Ag alloy nanoparticles using sucrose and their composition-dependent photocatalytic activity for the reduction of 4-nitrophenol

Abstract

Au-Ag alloy nanoparticles (NPs) less than 10 nm in size were synthesized using sucrose as a reductant and surfactant. Au-Ag alloy NPs with a homogeneous composition were continuously obtained by changing the synthesis time from 2 to 40 min in one pot. Based on the UV-Vis, ICP, TEM, HR-TEM, EDX and SAED analyses, the synthesis mechanism of Au-Ag alloy NPs was deduced. Under hydrolysis conditions, sucrose showed a stronger reducibility compared with glucose, fructose and their mixture. And the as-prepared Au-Ag alloy NPs exhibited a superior photocatalytic activity and stability for the reduction of 4-nitrophenol due to the abundant hydroxyl groups of sucrose and the synergistic effect between Au and Ag elements. The rate constant of 4-nitrophenol reduction could be linearly controlled by the composition of Au-Ag alloy NPs or their synthesis time. It was indicated that the photocatalytic activity of Au-Ag alloy NPs could be predetermined as early as their synthesis process. The above methods of controlling the rate constant provide promising routes for other photocatalytic reactions using bimetallic NPs as photocatalysts.

One-step chemical synthesis of Ag–Au alloy nanoparticles for modulating the catalytic hydrogenation reaction

“…Probably, the more reactive precursor, i.e., Au(III) is reduced first (due to higher reduction potential) and producing the nuclei followed by subsequent growth steps through monomer deposition of both species on those nuclei, resulting in Ag-Au alloy NPs of uniform composition. The above mentioned hypothesis is supported by similar observations and mechanisms reported earlier during the synthesis of Ag-Au alloy NPs with tunable size and surface plasmon resonance frequency (Liu et al 2011;Sun et al 2018).…”

“…Thus, it is quite complicated to distinguish them from their diffraction patterns as revealed from some of the literature reports (Berahim et al 2018;Yallappa et al 2015). The formation of heterostructures can also be ruled out due to the same lattices parameter of constituent atoms and instantaneous nucleation/growth processes (Sun et al 2018). Accordingly, we have confirmed the alloy formation from their absorption spectra as discussed above based on our own results and literatures cited in this work.…”

Co/Cu bimetallic ZIF as New heterogeneous catalyst for reduction of nitroarenes and dyes

“…Nitro compounds derived from industrial and agricultural wastewater are classified as toxic and environmental pollutants . Among them, nitrophenols have high solubility and stability in water, which lead to health hazards in human and animals . One way to solve this problem is the catalytic reduction of nitro compounds to the corresponding amines which are valuable chemicals in synthetic organic chemistry .…”

Enhancing Photooxidative Performance with Bi2O3 Nanoparticle-Modified BiVO4 Heterostructural Flowers

“…Sucrose, as an environmentfriendly and inexpensive soft template, changes the reactions among different ions and thus has been used for adjusting the morphologies of semiconductor materials. 28 In the present study, BiVO 4 −Bi 2 O 3 heterostructural flowers were fabricated by one-pot hydrothermal method. Sucrose was selected as a soft template because it plays a crucial role in the formation of the BiVO 4 −Bi 2 O 3 heterostructural flowers.…”

“…Hard templates, such as SiO 2 , require stricter conditions than soft templates, and thus have limited application. Sucrose, as an environment-friendly and inexpensive soft template, changes the reactions among different ions and thus has been used for adjusting the morphologies of semiconductor materials …”