激光液相烧蚀法制备纳米粒子研究进展 
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Significance Because of their special chemical properties, nanoparticles have a wide range of application prospects in optoelectronics, catalysis, medicine, military, and other fields. Researchers have developed many methods for preparing nanoparticles, such as solid phase method, liquid phase method, and gas phase method. These methods all have some shortcomings. For example, the liquid phase method is easy to introduce impurities difficult to be removed, the gas phase method has high costs and harsh conditions, and the solid phase method yields particles with uneven distribution and easy agglomeration. Different from these traditional preparation methods, pulsed laser ablation in liquid (PLAL) can create an ultra-high temperature and ultra-high pressure environment in the liquid, which provides a possibility to prepare nanoparticles that are difficult to be prepared under conventional conditions. It does not need to build complex experimental setups or add various catalysts. The morphology and size of the nanoparticles can be controlled by changing the parameters such as the wavelength, pulse width and frequency of laser and the type of solvents and target materials.
Progress At present, there are four major types of nanoparticles prepared by PLAL: metal nanoparticles, metal oxide nanoparticles, alloy nanoparticles, and non-metal nanoparticles. Metal nanoparticles mainly include noble metal nanoparticles and active metal nanoparticles. The chemical properties of noble metals are stable and the corresponding nanoparticles are easily prepared. Therefore, researchers are more inclined to prepare nanoparticles with a small size and a uniform distribution by controlling different parameters. However, active metal nanoparticles easily react with oxygen atoms in the solution to form metal oxide nanoparticles. To address this problem, researchers try to inhibit the oxidation of active metal nanoparticles by adding surfactants (sodium dodecyl sulfate, hexadecyl trimethyl ammonium bromide) or polymers to the solution. Some progress has been achieved, but the generation of metal oxide nanoparticles is inevitable. How to prepare highly active metal nanoparticles in the solution is still a difficulty for researchers. When metal oxide nanoparticles are prepared, the methods can be generally divided into two types: (1) with metal oxides as the targets, the metal oxide nanoparticles are produced by pulsed laser in the solution; (2) with pure metal as the target, the nanoparticles react with the solution to obtain the corresponding metal oxide nanoparticles. In addition, there are many types of oxides for the same metal. During the laser ablation process, metal oxide nanoparticles with different crystal forms or valence states may be produced in the solution. How to prepare a single type of metal oxide nanoparticle in the solution remains a question. Currently, most alloy nanoparticles prepared by PLAL are composed of two noble metals, or one noble metal and one active metal. Although alloy nanoparticles containing two active metals have been prepared, the products still contain some metal oxides or hydroxide nanoparticles. It is also found that alloy nanoparticles with a certain molar ratio can be prepared by adjusting the ratio of two metal elements in the alloy target. The non-metal nanoparticles prepared by PLAL mainly focus on carbon and silicon that generally do not react with the solution, so non-metal nanoparticles with special morphology can be prepared by adjusting energy, wavelength, and other parameters. Taking carbon as an example, graphene sheets or diamond nanoparticles can be prepared by PLAL. In addition to the above two materials, attempts have been made to obtain some other non-metal nanoparticles by PLAL.
Conclusions and Prospects Compared with the traditional nanoparticle preparation methods, PLAL has simple operation and strong applicability. In some cases, the size and structure of nanoparticles can be controlled by adjusting the laser parameters and other factors. With the increasing demand for nanomaterials, PLAL will be more widely used. However, PLAL also has some room for improvement, such as the low yield of nanoparticles. Researchers have taken a variety of measures to increase the yield of nanoparticles, such as changing the target shape, combining PLAL with microfluidic technology or ultrasonic treatment technology. Although the yield of nanoparticles has been increased, it can not meet the requirements of industrial production. Moreover, the preparation of pure metal nanoparticles by PLAL is still a challenge. Although many kinds of additives or solvents have been added, the desired results have not yet been achieved, which still needs much work. Furthermore, it is also an important research direction to combine PLAL with other nanoparticle preparation methods to prepare composite nanoparticles with excellent properties. In addition, PLAL has been applied to the preparation of nanoparticles for decades. Due to the complex reaction process, numerous factors affecting the morphology of nanoparticles, and a lack of effective characterization methods, the research on the growth mechanism of nanoparticles progresses slowly. In recent years, many researchers have put forward their own theoretical analysis in combination with some simulation methods, but the detailed reaction mechanism has not been conclusive until today. Therefore, researchers should focus on the basic principles of PLAL to provide a theoretical basis for the preparation of pure metal nanoparticles.
1 引言
随着科学技术的快速发展,传统的块状材料已难以满足社会需求,因此纳米技术与材料科学相结合的纳米材料应运而生,并将对未来的经济和社会发展产生巨大影响[1]。与传统的块状或微米级材料相比,纳米材料的晶粒尺寸更小,其诸多方面(如催化、光学、热学和磁化等)的性能都发生了改变,在信息、能源和**等领域具有重要应用。脉冲激光诞生于20世纪,普遍被应用于材料和医学等领域,也有研究人员将其应用于纳米材料的制备[2-3]。起初,激光烧蚀多在真空环境或者气氛环境下进行,例如,Alam等[4]利用激光烧蚀空气中的石墨颗粒成功地合成了金刚石。
近年来,激光液相烧蚀法制备纳米材料引起了人们的广泛关注。与激光气相烧蚀法不同,激光液相烧蚀法主要通过激光烧蚀液体中的靶材来达到制备纳米粒子的目的。由于液体环境的限制,激光与物质作用时的温度和压力更高,为制备常规条件下难以制备的材料提供了可能[5]。此外,可以通过引入某些添加剂,使产生的纳米粒子与液体介质发生反应,从而制备出性能更加优异的纳米复合材料。与传统的纳米粒子制备方法相比,激光液相烧蚀法具有绿色、简便、适用于大多数材料等优点,通过对溶剂和激光参数进行调控,可以获得具有特殊结构的纳米粒子。
为了给相关研究人员提供参考,本文介绍了激光液相烧蚀法的基本原理,总结了近年来国内外利用激光液相烧蚀法制备纳米粒子的研究进展,并指出了激光液相烧蚀法所面临的问题以及将来的发展趋势。
2 激光液相烧蚀法的基本原理
脉冲激光与固体靶材在液体环境中相互作用的过程极其复杂,包含物理反应和化学反应,迄今为止尚未形成公认的反应机理。根据激光脉宽的大小,目前研究人员常用的脉冲激光有三种,即毫秒脉冲激光(脉宽在1×10-3 s以上)、纳秒脉冲激光(脉宽在1×10-9~1×10-6 s之间)和超短脉冲激光(脉宽在1×10-15~1×10-9 s之间)。由于这三种脉冲激光的脉宽不同,因此它们在液体环境中与靶材的反应机理也有所不同,下面将逐一进行简要介绍。
2.1 毫秒脉冲激光
毫秒脉冲激光的脉宽较长,属于长脉冲激光,因此其峰值功率密度(106~107 W/cm2)远低于纳秒脉冲激光(108~1010 W/cm2)和飞秒脉冲激光(1012 W/cm2以上)[6-7]。由于具有较低的功率密度,毫秒激光与靶材作用后会产生熔融状金属液滴(如
图 1. 纳米液滴的形成和冷却[9]。 (a)纳米液滴的形成;(b)纳米液滴的冷却
Fig. 1. Formation and cooling of nanodroplets[9]. (a) Formation of nanodroplets; (b) cooling of nanodroplets
2.2 纳秒脉冲激光
Yang等[10]认为纳秒脉冲激光与靶材的反应过程包括等离子体羽流的产生、转化以及凝结等。如
图 2. 纳秒脉冲激光与靶材相互作用的机理示意图[11]
Fig. 2. Schematic of the interaction between nanosecond pulsed laser and target[11]
2.3 超短脉冲激光
超短脉冲激光分为皮秒脉冲激光和飞秒脉冲激光,前者与靶材的反应机理与纳秒脉冲激光相似。飞秒脉冲激光的峰值功率密度最高,与靶材之间的作用机理相对较为复杂。Xiao等[11]根据飞秒激光入射的功率密度将飞秒激光与靶材相互作用的过程分为四种,即相爆炸、碎裂、库仑爆炸和等离子体烧蚀。Shih等[12]结合经典分子动力学方法(MD)和双温模型(TTM)提出了混合原子连续介质模型,并对飞秒激光烧蚀沉积在水中硅片上的银薄膜的过程进行了模拟,预测了10 nm级颗粒的形成机制,预测结果与烧蚀过程中观察到的结果一致。Roeterdink等[13]结合飞行时间光谱对硅片进行了飞秒激光烧蚀实验,结果发现在硅片表面发生了库仑爆炸,随着功率密度的进一步增大,将会出现等离子体烧蚀现象,如
图 3. 飞秒脉冲激光与硅片的相互作用[11]。(a)不同能量密度下硅片表面发生的反应;(b)材料吸收激光能量;(c)电子从原子中剥离;(d)材料表面发生库伦爆炸
Fig. 3. Interaction between femtosecond pulsed laser and silicon wafer[11]. (a) Reaction on the surface of silicon wafer at different power densities; (b) material absorbs laser energy; (c) electrons stripped from atoms; (d) coulomb explosion on the surface of the material
3 激光液相烧蚀法的研究进展
3.1 激光液相烧蚀法制备金属纳米粒子
在众多的金属靶材中,Al、Fe和Cu等金属较为活泼,在溶液中制备其对应的金属纳米粒子较为困难。相比之下,Au、Ag和Pt等贵金属较为稳定,在烧蚀过程中不易与溶液发生反应,因此许多研究人员将其作为靶材通过激光烧蚀来制备对应的金属纳米粒子。
1993年,Fojtik等[14]首次利用红宝石激光对溶液中的Au和Ni薄膜进行烧蚀,成功制备了Au和Ni纳米粒子,并探究了激光能量与纳米粒子尺寸之间的关系。2001年,Mafuné等[15-16]利用脉冲激光对十二烷基硫酸钠(SDS)溶液中的Au片进行烧蚀,并研究了Au纳米粒子尺寸与溶液浓度之间的关系,结果发现,增加SDS溶液的浓度可以有效减小Au纳米粒子的粒径。Mafuné等认为这是由于SDS分子包覆在Au纳米粒子周围,阻止了其进一步的生长。他们还发现对含有Au纳米粒子的SDS溶液进行二次照射,会令Au纳米粒子的粒径进一步减小。此外,Mafuné等[17]还发现增大SDS溶液浓度同样会降低Ag纳米粒子的尺寸,但增大激光能量会导致Ag纳米粒子的粒径增大,这表明Ag纳米粒子的生长机制与Au纳米粒子存在差异。
Tan等[18]采用两种不同波长的脉冲激光对蒸馏水中的Au靶和Ag靶进行烧蚀,结果发现,与1064 nm激光相比,在532 nm激光烧蚀下制备的纳米粒子的光谱吸收峰强度更大。此外,在两种波长下增大激光能量都可以增大光谱吸收峰的强度。Hernández-Maya等[19]发现:当烧蚀时间固定为10 min时,增大激光能量会使Au纳米粒子的粒径不断增大;但当烧蚀时间固定为5 min时,粒子的粒径则随着能量的增加呈现出先增大后减小的趋势;当激光能量相同时,相比于10 min的烧蚀时间,5 min烧蚀时间下制备的粒子的粒径要小一些。为了提高纳米粒子的产率,Hu等[20]将超声处理与激光液相烧蚀法结合起来制备Ag纳米粒子,实验结果表明,超声处理不仅可以降低Ag纳米粒子的粒径,还可以提高其胶体悬浮液的稳定性。Hu等进行分析后发现,结合超声处理技术,脉冲激光可以在靶材表面形成体积更大的烧蚀坑,从而有效地提高了纳米粒子的产率。
与贵金属纳米粒子不同,利用激光液相烧蚀法在溶液中制备活泼金属纳米粒子存在较大困难,很多情况下制备的金属纳米粒子表面都存在氧化层。Altuwirqi等[21]首次利用白醋溶液作为溶剂,采用脉冲激光对其中的Al靶进行了烧蚀,结果发现,尽管在白醋溶液中无法制备出纯Al纳米粒子,但可以降低粒子中Al2O3的含量。Wei等[22]在加入适量抗坏血酸维生素C(VC)的甲醇溶液中对Al靶进行了烧蚀,结果发现,添加VC有助于Al纳米粒子形成更厚的碳壳,从而降低其被氧化的概率。Zhang等[23]以丙酮作为溶剂,利用脉冲激光对16种金属进行了烧蚀,结果显示,Cu、Ag、Au、Pd和Pt等金属的烧蚀产物为M@C(M代表金属)核壳结构的纳米粒子,Ti、V、Nb、Cr、Mo、W、Ni和Zr等金属的烧蚀产物为MC@C核壳结构的纳米粒子,Mn、Fe和Zn等金属的烧蚀产物为M/MOx@C核壳结构的纳米粒子。它们的形成机理如
图 4. 在丙酮中不同结构的碳化产物的形成机理图[23]
Fig. 4. Formation mechanism of carbonized products with different structures in acetone[23]
除了选择有机溶剂外,研究人员还通过向水溶液中添加表面活性剂或高聚物来改变溶液的性质,尝试制备出活泼金属纳米粒子。Zeng等[24]以不同浓度的SDS溶液和纯水作为溶剂进行了烧蚀实验,他们发现:增大SDS溶液的浓度可以有效降低Zn纳米粒子的氧化程度,并减小纳米粒子的粒径,产物由ZnO逐渐向Zn(OH)2转变;当SDS浓度升高到0.1 mol/L时,Zn纳米粒子的含量达到最大,ZnO纳米粒子则完全消失。纳米粒子形态与SDS溶液浓度之间的关系如
图 5. 不同浓度SDS溶液中纳米粒子的形成示意图[24]
Fig. 5. Formation of nanoparticles in different concentrations of SDS solutions[24]
Lee等[25]以十六烷基三甲基溴化铵(CTAB)溶液作为介质,利用脉冲激光烧蚀其中的Al靶材,成功制得了纯Al纳米粒子。他们对烧蚀产物进行X射线衍射分析后发现,提高CTAB溶液的浓度可以抑制Al(OH)3和Al2O3的产生,当CTAB溶液的浓度达到0.1 mol/L时,溶液中的纳米粒子为纯Al纳米粒子。
图 6. 不同浓度CTAB溶液中制备的纳米粒子的FE-SEM图[25]
Fig. 6. FE-SEM images of nanoparticles prepared in different concentrations of CTAB solutions[25]
Singh等[26]利用脉冲激光分别对聚乙烯吡咯烷酮(PVP)、聚乙烯醇(PVA)和聚乙二醇(PEG)三种高分子聚合物溶液中的Al靶材进行烧蚀,结果发现,在PVP和PVA溶液中的Al纳米粒子几乎没有发生氧化,而在PEG溶液中的Al纳米粒子发生了氧化。他们推断这是因为高分子聚合物分子链中的亲水基团吸附在Al纳米粒子表面,抑制了Al纳米粒子与水分子之间的氧化反应,如
图 7. PVP、PVA和PEG的分子结构以及对Al纳米粒子的保护示意图[26]
Fig. 7. Molecular structure of PVP, PVA, and PEG and protection for Al nanoparticles[26]
从
表 1. 采用激光液相烧蚀法制备金属纳米粒子
Table 1. Preparation of metal nanoparticles by laser ablation in liquid
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3.2 激光液相烧蚀法制备金属氧化物纳米粒子
与制备纯金属纳米粒子相比,利用激光液相烧蚀法制备金属氧化物纳米粒子较为简单,主要的制备方式分为两种:一种以金属氧化物作为靶材,利用脉冲激光直接在溶液中产生金属氧化物纳米粒子;另一种则是以纯金属作为靶材,利用纳米粒子与溶液之间的反应,获得对应的金属氧化物纳米粒子。1987年,Patil团队[29]首次采用高功率脉冲激光在水中合成了亚稳态氧化铁纳米粒子,这项具有开创性的实验为金属氧化物纳米粒子的制备开辟了新途径。
Chen等[30]利用脉冲激光对FeCl2溶液中的Fe靶材进行烧蚀,成功制备出了具有双层六方密排(DHCP)结构的高压铁相和γ-Fe2O3纳米粒子,但由于DHCP结构的铁相属于亚稳态物质,在6个月之后,它就完全转变成了γ-Fe2O3粒子。这表明,激光液相烧蚀法可以用来制备常温条件下难以合成的亚稳态物质。Maneeratanasarn等[31]将α-Fe2O3粉末压制成靶材,分别以乙醇、去离子水和丙酮作为溶剂,进行了激光烧蚀实验。他们发现,在丙酮中制备的纳米粒子的粒径最小,推测是因为丙酮的偶极矩较大,纳米粒子在生长过程中受到的静电斥力较大,因此粒径最小。此外,他们还发现,在丙酮和乙醇中制备的产物为γ-Fe2O3纳米粒子,而在水中制备的产物为α-Fe2O3纳米粒子。这表明,利用激光液相烧蚀法可以改变纳米粒子的晶型。
Ni及其氧化物粒子具有特殊的性质,在药物合成、生物传感器等领域被广泛应用,因此,许多研究人员开始利用激光液相烧蚀法制备Ni及其氧化物纳米粒子。Mahdi等[32]发现,增大激光能量虽然可以减小NiO纳米粒子的平均粒径,但却会使部分NiO纳米粒子的粒径增大。Hadi等[33]发现延长烧蚀时间不仅会对NiO纳米粒子的形态产生影响,还会使其粒径增大。Nikov等[34]在激光液相烧蚀装置中施加外部磁场后发现,施加外部磁场可以控制NiO纳米粒子的产物结构,如
图 8. 在相同条件下于不同溶液中制备的NiO粒子的光学显微镜图、扫描电镜图以及对应的粒径分布直方图[34]。(a)蒸馏水; (b)乙醇溶液
Fig. 8. Optical microscopy and scanning electron microscopy images and corresponding particle size distribution histograms of NiO particles prepared in different solutions under the same condition[34]. (a) Distilled water; (b) ethanol solution
CuO和Cu2O纳米粒子在催化合成和****等方面被广泛应用。近些年,研究人员开始采用激光液相烧蚀法制备Cu的氧化物纳米粒子。Rawat等[35]利用激光液相烧蚀技术成功地在去离子水中制备了空心CuO纳米粒子,并推测空心纳米粒子的形成是柯肯达尔效应导致的,柯肯达尔效应与水中的溶解氧密切相关。此外,Rawat等以乙二醇溶液作为溶剂进行了对比实验,并证实了上述推断。在另一项研究中,Rawat等[36]发现相比于波长为1064 nm的激光,波长为532 nm的激光可以制备出粒径更小的CuO纳米粒子,而且纯化处理可以进一步降低纳米粒子的粒径,但也会加剧纳米粒子的氧化程度。为了提高纳米粒子的产量,Al-Antaki等[37]将激光液相烧蚀装置进行了改进,改进后的装置如
图 9. 激光液相烧蚀法在动态微流体中制备纳米粒子的示意图[37]。 (a)实验装置示意图;(b)单次操作模式;(c)连续操作模式
Fig. 9. Schematic of preparation of nanoparticles by laser ablation in dynamic microfluidics[37]. (a) Experimental setup; (b) confined mode of operation; (c) continuous mode of operation
Zhang等[38]利用脉冲激光对蒸馏水中的Cu靶材进行烧蚀,结果显示:相比于5 ns和30 fs的脉冲激光,采用200 ps的脉冲激光制备的纳米粒子的产率最高,但稳定性较差(制备的胶体悬浮液的颜色会随着时间的延长而逐渐由绿色转变为棕色),这说明溶液中的Cu纳米粒子逐渐被氧化成CuO/Cu2O纳米粒子。从
图 10. 不同脉宽条件下制备的Cu纳米粒子的扫描电镜图[38]。(a)(b) 5 ns; (c)(d) 200 ps; (e)(f) 30 fs
Fig. 10. Scanning electron microscopy images of Cu nanoparticles prepared with different pulse widths[38]. (a)(b) 5 ns; (c)(d) 200 ps; (e)(f) 30 fs
Goncharova等[39]采用激光液相烧蚀法分别在4种溶剂(去离子水、NaOH溶液、H2O2溶液和 无水乙醇)中制备了纳米粒子,如
图 11. 纳米粒子在不同溶液中的生成示意图[39]。(a)去离子水; (b) NaOH溶液; (c) H2O2溶液; (d)无水乙醇
Fig. 11. Formation of nanoparticle in different solutions[39]. (a) Deionized water; (b) sodium hydroxide solution; (c) hydrogen peroxide solution; (d) anhydrous ethanol
除上述内容外,研究人员还利用激光液相烧蚀法合成了Zn
表 2. 采用激光液相烧蚀法制备金属氧化物纳米粒子
Table 2. Preparation of metal oxide nanoparticles by laser ablation in liquid
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3.3 激光液相烧蚀法制备合金纳米粒子
相比于单金属纳米粒子,某些合金纳米粒子具有更加优异的性能,可以通过改变粒子中的元素占比来调节粒子的光学性能和催化性能[48]。研究人员探索出了许多制备合金纳米粒子的方法,但是传统化学法的实验条件比较苛刻,产物容易发生相分离的现象,因此利用激光液相烧蚀法制备合金纳米粒子引起了研究人员的注意[49]。
由于Au和Ag的晶格系数相近,因此研究人员在Au-Ag合金纳米粒子的合成方面进行大量的工作。Besner等[50]利用飞秒激光在右旋糖酐溶液中制备了Au-Ag合金纳米粒子,他们发现,合金纳米粒子中Au元素的占比越高,其抗氧化能力越强。Menéndez-Manjón等[51]以甲基丙烯酸甲酯(MMA)溶液作为溶剂,利用脉冲激光烧蚀其中的Au-Ag合金薄膜成功制备了Au-Ag合金纳米粒子,他们还证明了通过激光烧蚀含有Au和Ag纳米粒子的胶体悬浮液也可以制备Au-Ag合金纳米粒子。Compagnini等[52]利用激光液相烧蚀法在水中成功制备出了Au@Ag核壳合金纳米粒子,但核中还包含有少量Ag元素。随着Au-Ag合金纳米粒子的成功制备,研究人员开始探究Ag-Au合金纳米粒子的形成条件。Neumeister等[53]采用三种不同的实验方案进行了激光烧蚀实验,如
除Au-Ag合金纳米粒子外,研究人员还将其他贵金属以及活泼金属作为制备合金纳米粒子的靶材。Zhang等[54]将Au粉和Pt粉压制成Pt-Au合金靶材,利用激光液相烧蚀法在水中成功制备了具有面心立方结构的Pt-Au合金纳米粒子。他们发现:靶材中Pt含量的升高有利于生成小尺寸的合金纳米粒子;当溶液的pH在4~11之间且激光能量密度为4 ~150 J/cm2时,合金纳米粒子中两种元素的物质的量之比与靶材中的相同。Malviya等[55]利用激光液相烧蚀法在PVP溶液中成功制备了Ag-Cu合金纳米粒子,他们发现,增加靶材中Cu的含量会使烧蚀效率下降,而且会影响纳米粒子的形貌,最终形成小尺寸的Cu@Ag的核壳纳米粒子。Wagener等[56]将去离子水、丙酮、MMA分别作为溶液,对Fe-Au合金靶材进行了激光液相烧蚀实验,实验结果如
图 13. 在不同溶液中制备的合金纳米粒子的粒径分布直方图以及对应的流体动力学直径、Zeta电位、费雷特直径[56]。(a)在丙酮中制备的合金纳米粒子的粒径分布直方图;(b)在MMA中制备的合金纳米粒子的粒径分布直方图; (c)在去离子水中制备的合金纳米粒子的粒径分布直方图;(d)流体动力学直径、Zeta电位和费雷特直径
Fig. 13. Histogram of particle size distribution of alloy nanoparticles prepared in different solutions and corresponding hydrodynamic diameter, Zeta potential, and Ferret diameter[56]. (a) Histogram of particle size distribution of alloy nanoparticles prepared in acetone; (b) histogram of particle size distribution of alloy nanoparticles prepared in MMA; (c) histogram of particle size distribution of alloy nanoparticles prepared in deionized water; (d) h
Wang等[57]将不同比例的Pb粉和Zn粉压制成合金靶材(其中Pb和Zn的物质的量比分别为2∶1、1∶1和1∶2),利用毫秒脉冲激光成功地在无水乙醇溶液中制备了非均相的Pb/Zn纳米粒子。由
图 14. 烧蚀Pb与Zn物质的量比为2∶1、1∶1、1∶2的合金靶材制备的纳米粒子的TEM图[57]。(a)(c)(e)低倍TEM图;(b)(d)(f)高倍TEM图
Fig. 14. TEM images of nanoparticles prepared by ablating alloy targets with different molar ratios of Pb to Zn[57]. (a)(c)(e) Lowly enlarged TEM; (b)(d)(f) highly enlarged TEM
表 3. 采用激光液相烧蚀法制备合金纳米粒子
Table 3. Preparation of alloy nanoparticles by laser ablation in liquid
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3.4 激光液相烧蚀法制备非金属纳米粒子
作为一种新型的纳米材料制备方法,激光液相烧蚀法不仅可用于制备金属(氧化物)纳米粒子,还可用于制备非金属纳米粒子。
1992年,Ogale等[62]利用纳秒脉冲激光对苯溶液中的石墨靶材进行烧蚀,成功制备了金刚石粒子,自此以后,金刚石纳米粒子及其相关材料的制备成为了国内外的研究热点。随后,Wang等[63]也在水中成功合成了金刚石纳米粒子。Yang等[64]和Wang等[65]利用高功率脉冲激光分别在水和丙酮溶液中制备了金刚石纳米粒子,这些纳米粒子含有立方相和六方相两种不同的结构。
近年来,研究人员对激光液相烧蚀法制备碳纳米材料又有了新的认识。Sadeghi等[66]采用4种不同的溶剂,用纳秒激光对其中的石墨板进行烧蚀,结果发现,在水中生成的石墨烯薄片数量最多,而在乙醇中生成的碳纳米颗粒的数量最多,如
Si纳米粒子具有优异的性能,在光电器件、生物医学等方面具有广泛应用。尽管研究人员已经开发出了制备Si纳米粒子的多种化学法和物理法,但化学法的操作步骤繁多,且涉及的化学试剂较多。因此,近几年利用激光液相烧蚀法制备Si纳米粒子引起了研究人员的极大兴趣[69]。
Chewchinda等[70]采用两种不同波长的脉冲激光烧蚀乙醇溶液中Si片,结果发现,532 nm激光有利于制备更多的Si纳米粒子。TEM图像显示,两种波长下制备的Si纳米粒子均为圆球形,但532 nm激光制备的粒子具有更小的粒径。Abderrafi等[71]以氯仿溶液为溶剂,用Nd∶YAG脉冲激光对其中的Si片进行烧蚀(第一步),随后将第一步制备的Si纳米粒子放入含有异丙醇、氢氟酸和正己烷的混合溶液(体积比为3∶1∶3)中,进行超声处理(第二步)。他们发现,第二步处理使Si纳米粒子的平均粒径大幅减小。他们认为,超声处理可以引发溶液中尺寸较大的多晶颗粒的分解,释放出小尺寸的Si纳米晶体,从而降低了溶液中粒子的尺寸。Hamad等[72]探究了溶剂种类对Si纳米粒子形态的影响,结果发现,在丙酮和水中的烧蚀产物分别为纯Si纳米粒子和Si/SiO2复合纳米粒子,而在二氯甲烷和氯仿中的烧蚀产物均为Si/C复合纳米粒子。此外,尽管4种溶剂中的产物均为球形纳米粒子,但在丙酮中的Si纳米粒子的平均粒径远低于其他三者。关凯珉等[73]将激光液相烧蚀法与微流控技术相结合,在硅基微流控芯片中快速制备了不同粒径的Si纳米结构,将激光液相烧蚀法的最高制备效率提高了30%以上,为其将来的工业化生产提供了新的路线。Intartaglia等[74]系统地研究了激光能量、烧蚀时间、激光波长等参数对Si纳米粒子形态的影响。如
图 16. 不同波长下Si靶烧蚀质量与激光脉冲数之间的关系图[74]。(a)1064 nm; (b)355 nm
Fig. 16. Ablated silicon mass as function of the number of laser pulses in different wavelengths[74]. (a) 1064 nm; (b) 355 nm
表 4. 采用激光液相烧蚀法制备非金属纳米粒子
Table 4. Preparation of non-metallic nanoparticles by laser ablation in liquid
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4 结束语
激光液相烧蚀法作为一种新型的纳米材料制备方法,具有操作简便、绿色环保以及适用性广等特点,在制备纳米粒子方面具有很多传统方法无法比拟的优势。随着人们对纳米材料需求的不断增加,激光液相烧蚀法将具有更加广阔的应用前景。
但激光液相烧蚀法在制备纳米粒子方面仍存在一些急需解决的问题,比如,纳米粒子的产率问题。目前,采用激光液相烧蚀法制备纳米粒子的最高产率只停留在毫克(每小时)级别,这严重阻碍了其在工业领域的推广应用。尽管研究人员采取了多种措施进行改进,如增大激光能量、改变靶材形状、改进实验装置等,但效果并不理想。此外还有活泼金属纳米粒子的制备问题。目前利用激光液相烧蚀法制备Al、Cu、Fe等活泼金属纳米粒子还存在一定困难,寻找合适的溶剂或添加剂还需要长时间探索。此外,尽管近年来研究人员已经开始将探究激光液相烧蚀法的详细原理作为研究重点,但仍未形成一个公认的纳米粒子的生长机制,这一方面还需要投入大量的工作。
综上所述,激光液相烧蚀法在制备纳米粒子方面具有巨大潜力,但未来仍需要在以下几个方面进行深入研究:
1)通过改进实验装置和优化实验参数等方式,在保证纳米粒子粒径和结构不变的情况下,进一步提高纳米粒子的产率。
2)结合模拟手段,深入探究激光液相烧蚀过程中纳米粒子的生成机理,为制备某些具有特殊性能的亚稳态物质提供理论基础。
3)研究波长、脉宽、能量、溶剂等与纳米粒子形态结构之间的关系,选择更加有效的溶剂或添加剂来制备活泼金属的纯金属纳米粒子。
4) 将激光液相烧蚀法与水热法、电泳沉积法等材料制备方法相结合,制备性能优异的纳米复合材料。
[1] 张盛强, 汪建义, 王大辉, 等. 纳米金属材料的研究进展[J]. 材料导报, 2011, 25(S1): 5-9,20.
Zhang S Q, Wang J Y, Wang D H, et al. Recent progress on nano metallic materials[J]. Materials Review, 2011, 25(S1): 5-9,20.
[2] 牛凯阳. 毫秒脉冲激光可控合成纳米结构: 工艺、材料、性能与机理研究[D]. 天津: 天津大学, 2011: 1- 11.
Niu KY. Controllabe synthesis of nanostuctures by millisecond pulsed laser:study on processes, materials, properties and mechanisms[D]. Tianjin: Tianjin University, 2011: 1- 11.
[3] 邓泽超, 刘建东, 王旭, 等. 真空环境中脉冲激光烧蚀制备纳米银晶薄膜的生长特性[J]. 中国激光, 2019, 46(9): 0903003.
[4] Alam M. DebRoy T, Roy R, et al. Diamond formation in air by the Fedoseev-Derjaguin laser process[J]. Carbon, 1989, 27(2): 289-294.
[5] 谭德志. 液相脉冲激光烧蚀法制备功能纳米材料[D]. 杭州: 浙江大学, 2014: 8- 39.
Tan DZ. Preparation of functional nanomaterials by pulsed laser ablation in liquid[D]. Hangzhou: Zhejiang University, 2014: 8- 39.
[12] Shih C Y, Wu C P, Shugaev M V, et al. Atomistic modeling of nanoparticle generation in short pulse laser ablation of thin metal films in water[J]. Journal of Colloid and Interface Science, 2017, 489: 3-17.
[13] Roeterdink W G, Juurlink L B F, Vaughan O P H, et al. Coulomb explosion in femtosecond laser ablation of Si(111)[J]. Applied Physics Letters, 2003, 82(23): 4190-4192.
[16] Mafuné F, Kohno J Y, Takeda Y, et al. Dissociation and aggregation of gold nanoparticles under laser irradiation[J]. The Journal of Physical Chemistry B, 2001, 105(38): 9050-9056.
[19] Hernández-MayaM, Rivera-QuinteroP, OspinaR, et al.Ablation energy, water volume and ablation time: gold nanoparticles obtained through by pulsed laser ablation in liquid[C] //5th International Meeting for Researchers in Materials and Plasma Technology (5th IMRMPT) May. 28-31, 2019, San José de Cúcuta, Colombia. [S.l.]: IOP Publishing, 2019, 1386( 1): 012062.
[25] Lee S, Shin J H, Choi M Y. Watching the growth of aluminum hydroxide nanoparticles from aluminum nanoparticles synthesized by pulsed laser ablation in aqueous surfactant solution[J]. Journal of Nanoparticle Research, 2013, 15(3): 1473.
[26] Singh R, Soni R K. Laser synthesis of aluminium nanoparticles in biocompatible polymer solutions[J]. Applied Physics A, 2014, 116(2): 689-701.
[27] 杜传梅, 吕良宏, 张明旭. 飞秒激光烧蚀氯金酸水溶液制备金纳米粒子[J]. 中国激光, 2017, 44(8): 0803003.
[28] Moniri S, Ghoranneviss M, Hantehzadeh M R, et al. Synthesis of platinum nanoparticles by nanosecond laser irradiation of bulk Pt in different polar solvents[J]. Research on Chemical Intermediates, 2017, 43(5): 3015-3034.
[31] Maneeratanasarn P, Khai T V, Kim S Y, et al. Synthesis of phase-controlled iron oxide nanoparticles by pulsed laser ablation in different liquid media[J]. Physica Status Solidi (a), 2013, 210(3): 563-569.
[32] Mahdi RO, Hadi AA, Taha JM, et al.Preparation of nickel oxide nanoparticles prepared by laser ablation in water[C] //2nd International Conference on Materials Engineering & Science (IConMEAS 2019), Baghdad, Iraq. [S.l.]: AIP Publishing, 2020: 020309.
[33] Hadi AA, Taha JM, Mahdi RO, et al.Influence of laser pulse on properties of NiO NPs prepared by laser ablation in liquid[C] //2nd International Conference on Materials Engineering & Science (IConMEAS 2019),Baghdad, Iraq. [S.l.]: AIP Publishing, 2020: 020308.
[43] Zamora-Romero N. Camacho-Lopez M A, Camacho-Lopez M, et al. Molybdenum nanoparticles generation by pulsed laser ablation and effects of oxidation due to aging[J]. Journal of Alloys and Compounds, 2019, 788: 666-671.
[45] Enríquez-Sánchez N. Vilchis-Nestor A R, Camacho-López S, et al. Influence of ablation time on the formation of manganese oxides synthesized by laser ablation of solids in liquids[J]. Optics & Laser Technology, 2020, 131: 106418.
[58] 李双浩, 赵艳. 激光液相烧蚀法制备金核银壳纳米结构及其性能的研究[J]. 中国激光, 2014, 41(7): 0706001.
[61] PatraN, PatilR, SharmaA, et al.Comparative study on Cu, Al and Cu-Al alloy nanoparticles synthesized through underwater laser ablation technique[C] //The 3rd International Conference on Materials and Manufacturing Engineering, March.8-9, 2018, Tamilnadu, India. [S.l.]: IOP Publishing, 2018: 012046.
[63] 王育煌, 余荣清, 刘朝阳, 等. 纳米金刚石球晶的激光溅射产生与透射电镜表征[J]. 高等学校化学学报, 1997, 18(1): 124-126.
Wang Y H, Yu R Q, Liu Z Y, et al. Production of diamond nanospherulite at carbon-water interface by laser ablation and its characterization by TEM[J]. Chemical Research in Chinese Universities, 1997, 18(1): 124-126.
[68] Escobar-Alarcón L. Espinosa-Pesqueira M E, Solis-Casados D A, et al. Two-dimensional carbon nanostructures obtained by laser ablation in liquid: effect of an ultrasonic field[J]. Applied Physics A, 2018, 124(2): 141.
[69] Intartaglia R, Bagga K, Scotto M, et al. Luminescent silicon nanoparticles prepared by ultra short pulsed laser ablation in liquid for imaging applications[J]. Optical Materials Express, 2012, 2(5): 510-518.
[70] Chewchinda P, Tsuge T, Funakubo H, et al. Laser wavelength effect on size and morphology of silicon nanoparticles prepared by laser ablation in liquid[J]. Japanese Journal of Applied Physics, 2013, 52(2R): 025001.
[71] Abderrafi K, García-Calzada R, Gongalsky M B, et al. Silicon nanocrystals produced by nanosecond laser ablation in an organic liquid[J]. The Journal of Physical Chemistry C, 2011, 115(12): 5147-5151.
[73] 关凯珉, 刘晋桥, 徐颖, 等. 基于微流控技术的高效液相脉冲激光烧蚀法[J]. 中国激光, 2017, 44(4): 0402006.
Article Outline
陈永义, 鲍立荣, 汪辉, 宁政, 钟贤东, 曹金乐, 沈瑞琪, 张伟. 激光液相烧蚀法制备纳米粒子研究进展[J]. 中国激光, 2021, 48(6): 0600002. Yongyi Chen, Lirong Bao, Hui Wang, Zheng Ning, Xiandong Zhong, Jinle Cao, Ruiqi Shen, Wei Zhang. Research Progress in Preparation of Nanoparticles by Laser Ablation in Liquid[J]. Chinese Journal of Lasers, 2021, 48(6): 0600002.
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