Microfluidic synthesis of Ag@Cu2O core-shell nanoparticles with enhanced photocatalytic activity
Microfluidic synthesis of Ag@Cu2O core-shell nanoparticles with enhanced photocatalytic activity
复制标题
微流控合成具有增强光催化活性的Ag@Cu2O核壳纳米颗粒
DOI：
10.1016/j.jcis.2016.09.051
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发表时间：
2017-01-15
影响因子：
9.9
通讯作者：
Chen, Guangwen
中科院分区：
文献类型：
--
作者：
Tao, Sha;Yang, Mei;Chen, Guangwen
发展了一种基于微流控技术的Ag@Cu2O核壳纳米粒子（NPs）的连续合成方法。仅用32秒就获得Ag@Cu2O核-壳纳米颗粒，表明这种基于微流体的方法的高效率。以三角形Ag纳米棱柱为核心，通过抗坏血酸还原Cu（OH）（4），生长出Cu 2 O.采用XRD、TEM、SEM、HAADF-STEM、EDX、HRTEM、UV-vis光谱和N2吸附-脱附等手段对样品进行了表征。表征结果表明，所合成的Ag@Cu2O核-壳纳米颗粒具有多晶壳结构，壳结构由大量Cu 2 O畴外延生长在三角形Ag纳米柱上构成。结果表明，柠檬酸三钠与AgNO 3的摩尔比、H2 O2与AgNO 3的摩尔比、NaOH与CuSO 4的摩尔比、抗坏血酸与CuSO 4的摩尔比以及AgNO 3与CuSO 4的摩尔比对Ag@Cu2O核壳纳米粒子的合成有显著影响。此外，Ag@Cu2O核-壳纳米粒子对可见光驱动的甲基橙橙子的降解表现出比纯Cu 2 O纳米粒子更优越的上级催化活性. Ag@Cu2O核-壳纳米颗粒的光催化活性增强归因于更大的BET表面积和改善的电荷分离效率。捕获实验表明，空穴和超氧阴离子自由基是Ag@Cu2O核壳纳米粒子光降解甲基橙的主要活性物种.此外，Ag@Cu2O核-壳纳米颗粒在循环测试中没有显示出明显的失活。(C)2016 Elsevier Inc. All rights reserved.
A microfluidic-based method for the continuous synthesis of Ag@Cu2O core-shell nanoparticles (NPs) has been developed. It only took 32 s to obtain Ag@Cu2O core-shell NPs, indicating a high efficiency of this microfluidic-based method. Triangular Ag nanoprisms were employed as the cores for the overgrowth of Cu2O through the reduction of Cu(OH)(4) with ascorbic acid. The as-synthesized samples were characterized by XRD, TEM, SEM, HAADF-STEM, EDX, HRTEM, UV-vis spectra and N-2 adsorption-desorption. The characterization results revealed that the as-synthesized Ag@Cu2O core-shell NPs exhibited a welldefined core-shell nanostructure with a polycrystalline shell, which was composed of numbers of Cu2O domains epitaxially growing on the triangular Ag nanoprism. It was concluded that the synthesis parameters such as the molar ratio of trisodium citrate to AgNO3, H2O2 to AgNO3, NaOH to CuSO4, ascorbic acid to CuSO4 and AgNO3 to CuSO4 had significant effect on the synthesis of Ag@Cu2O core-shell NPs. Moreover, Ag@Cu2O core-shell NPs exhibited superior catalytic activity in comparison with pristine Cu2O NPs towards the visible light-driven degradation of methyl orange. This enhanced photocatalytic activity of Ag@Cu2O core-shell NPs was attributed to the larger BET surface area and improved charge separation efficiency. The trapping experiment indicated that holes and superoxide anion radicals were the major reactive species in the photodegradation of methyl orange over Ag@Cu2O core-shell NPs. In addition, Ag@Cu2O core-shell NPs showed no obvious deactivation in the cyclic test. (C) 2016 Elsevier Inc. All rights reserved.