纳米棒
催化作用
表面等离子共振
4-硝基苯酚
反应速率常数
纳米颗粒
形态学(生物学)
化学
胶体金
纳米技术
材料科学
分析化学(期刊)
选择性催化还原
核化学
化学工程
动力学
有机化学
物理
量子力学
生物
工程类
遗传学
作者
Ang Ma,Weiye Yang,Kunpeng Gao,Junqi Tang
出处
期刊:Chemosphere
[Elsevier]
日期:2023-01-01
卷期号:310: 136800-136800
被引量:12
标识
DOI:10.1016/j.chemosphere.2022.136800
摘要
Anisotropic gold nanostructures have attracted great attention in different fields including catalysis. Thermodynamically driven selective surface growth offers a reliable and reproducible method for anisotropic gold nanoparticle synthesis with specific morphologies. Herein, monocrystalline concave gold nano-arrows (AuCNAs) are prepared by the over-growth method using Au nanorods (AuNRs) as seeds. The as-prepared AuCNAs consist of a biconical head and four concave structures. Interestingly, silver ions (Ag+) concentration significantly affects the product morphology by tuning the peak positions of surface plasmon resonance (SPR), aspect ratio, arrow, and concave morphology of AuCNAs. The position of longitudinal SPR peaks is observed at 810, 805 and 782 nm at [Ag+]/[Au3+] molar ratios of 1:2, 1:1, and 2:1, respectively. Diameters and lengths of AuCNAs varied from 25 nm to 36 nm; 104 nm, 78 nm, and 120 nm, respectively. Additionally, the AuCNAs are applied for the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in presence of excess NaBH4. Compared to gold nanorods (AuNRs), the prepared AuCNAs catalyst shows excellent catalytic activity, demonstrating that concave structures and sharp corners significantly enhance the catalytic activity. The value of pseudo-first-order reaction kinetic constants (kapp) increased from 0.0051 to 0.0195 s-1 with increasing catalyst valume from 7.5 to 37.5 μL. The highest normalized reaction rate constant (Knor) and turnover frequency (TOF) reach 5.84 × 104 min-1 mmol-1 and 443.47 h-1, respectively, at [Ag+]/[Au3+] ratio of 1:1 in AuCNAs catalyst. This study expands catalytic applications of anisotropic gold nanostructures and widens their potential application areas, such as surface plasmon exciton photonics, biomedical photonics, and photocatalysis.
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