Reduction of silver ions to form silver nanoparticles by redox-active organic molecules: coupled impact of the redox state and environmental factors,Environmental Science: Nano

当前位置： X-MOL 学术 › Environ. Sci.: Nano › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Reduction of silver ions to form silver nanoparticles by redox-active organic molecules: coupled impact of the redox state and environmental factors
Environmental Science: Nano ( IF 5.8 ) Pub Date : 2020-12-9 , DOI: 10.1039/d0en00820f
Feng Dong _{1,

2,

3,

4,

5} , Chao Wu _{5,

6,

7,

8,

9} , Ai-Jun Miao _{5,

6,

7,

8,

9} , Ke Pan _{1,

2,

3,

4,

5}

Affiliation

The release of silver ions (Ag⁺) is an important process in determining the environmental fate and toxic effects of silver nanoparticles (AgNPs), but the released Ag⁺ can be reduced to form new AgNPs in environments. Here the reduction of Ag⁺ by redox-active organic molecules to form AgNPs under different lighting and oxygen conditions was investigated using anthraquinonoe-2,6-disulphonate (AQDS) and nicotinamide adenine dinucleotide (NAD⁺) as representatives. In anaerobic environments, oxidized AQDS (AQDS_ox) and NAD⁺ failed to reduce Ag⁺ to form AgNPs, whereas reduced AQDS (AQDS_red) and NAD⁺ (NADH) produced a concentration-dependent AgNP production pattern, underlining a key role of the redox state in Ag⁺ reduction by organics. The presence of O₂ diminished the reducing capacity of NADH and AQDS_red, probably due to their oxidation by O₂. However, under UV light, the AgNP formation rate was dramatically enhanced in AQDS, independent of O₂. Our results revealed that the Ag⁺ photoreduction was mainly attributed to the photoexcited AQDS, not the radical intermediates. For the complex organic humic acid (HA), and consistent with the phenomena in AQDS, the reduced HA (HA_red) reduced Ag⁺ at a much faster rate than the native HA (HA_ox) in anaerobic and dark environments, and the amounts of AgNPs produced by HA_red decreased in oxic environments. UV illumination enabled significant Ag⁺ reduction in both HA_ox and HA_red, and O₂ promoted the AgNP formation. Our study systematically revealed different Ag⁺-reduction pathways to form AgNPs, with an organic's redox state and environmental factors having a combined effect.

中文翻译：

氧化还原活性有机分子还原银离子形成银纳米粒子：氧化还原状态和环境因素的耦合影响

银离子（Ag ⁺）的释放是确定银纳米颗粒（AgNPs）的环境命运和毒性影响的重要过程，但是释放的Ag ⁺可以被还原以在环境中形成新的AgNPs。在这里，以蒽醌-2,6-二磺酸盐（AQDS）和烟酰胺腺嘌呤二核苷酸（NAD ⁺）为代表，研究了氧化还原活性有机分子在不同的光照和氧气条件下还原Ag ⁺形成AgNPs的方法。在厌氧环境中，氧化的AQDS（AQDS _ox）和NAD ⁺无法还原Ag ⁺形成AgNPs，而还原的AQDS（AQDS _red）和NAD ⁺（NADH）产生了浓度依赖性的AgNP生产模式，强调了氧化还原状态在有机物还原Ag ^+中的关键作用。O ₂的存在降低了NADH和AQDS _red的还原能力，这可能是由于它们被O ₂氧化了。但是，在紫外线下，AQDS中的AgNP形成速率显着提高，而与O ₂无关。我们的结果表明，Ag ⁺的光还原主要归因于光激发的AQDS，而不是自由基中间体。对于复杂的有机腐殖酸（HA），并与AQDS中的现象一致，还原的HA（HA _red）还原了Ag ⁺在厌氧和黑暗环境中，其速度要比天然HA（HA _ox）快得多，并且在有氧环境中，由HA _red产生的AgNPs数量减少。紫外线照射可显着降低HA _ox和HA _red中的Ag ⁺含量，而O ₂促进AgNP的形成。我们的研究系统地揭示了形成AgNPs的不同的Ag ^+-还原途径，其中有机物的氧化还原状态和环境因素具有综合作用。

更新日期：2020-12-21

点击分享查看原文

点击收藏

阅读更多本刊最新论文