Rochester researchers have documented the pulsed-laser-in-liquid technique’s multiple advantages over traditional wet lab methods.
Chemical catalysts are the change agents behind the production of just about everything we use in our daily lives, 从塑料到处方药. 当合适的催化剂与合适的化合物混合时, 分子之间的相互作用本来需要几年的时间，但现在只需几秒钟.
然而, developing even one catalyst material to trigger this precise choreography of atoms can take months, 甚至几年, when using traditional wet chemistry procedures that use only chemical reactions, 通常在液相中, 培养纳米颗粒.
澳门威尼斯人网上赌场 researchers say there is a way to shorten that process dramatically—by instead using pulsed lasers in liquids to quickly create carefully tuned, systematic arrays of nanoparticles that can be easily compared and tested for use as catalysts.
该过程在 化学评论 article by 阿斯特丽德穆勒的助理教授 化学工程 在 澳门威尼斯人网上赌场 谁在她的可持续能源解决方案的工作中采用了这种技术. 她实验室的三名博士生和合著者瑞兰德·福赛斯, 康纳考克斯, and Madeleine Wilsey—conducted an exhaustive review of almost 600 previous papers involving the use of pulsed lasers in liquids. 结果是, 他们的文章最全面, 对1987年首次开发的一项技术的最新调查.
脉冲激光在液体和 不可缺少的工具 发现催化剂
那么脉冲激光在液体中的合成是如何工作的呢?
- 脉冲激光对准浸在液体中的固体材料. This creates a high-temperature, high-pressure plasma near the surface of the solid.
- 当等离子体衰变时, 它使周围液体中的分子蒸发, 导致空化泡. 在泡沫中, chemical reactions begin to occur between particles from the liquid and particles that were ablated, 或者被敲松, 从固体开始.
- 经过周期性的扩张和收缩, 空化泡剧烈内爆, 造成冲击波和快速冷却. Nanoparticles from the bubble condense in small clusters that are injected into the surrounding liquid and become stable.
The pulsed-laser-in-liquids technique offers multiple advantages over traditional wet-lab synthesis of nano材料. 根据她的说法:
- 因为反应主要局限于空化泡内, 得到的纳米颗粒具有非常均匀的性质. “每一个被制造出来的粒子都是在相同的条件下产生的，”她说.
- The properties of the nanoparticles can be easily fine-tuned by adjusting the laser pulses and the chemical compositions of the solid and surrounding fluid.
- Laser-made nanocatalysts are intrinsically more active than those obtained by wet chemistry methods.
Metastable nano材料 with non-equilibrium structures and compositions can easily be produced. 这种材料不能在中等温度和压力下制造. - 激光合成可以远程控制, 增加大规模工业应用的潜力.
- Pulsed-laser-in-liquids synthesis of nano材料 is also far more rapid than traditional methods. 该技术可以在一个小时或更短的时间内制备大量的纳米颗粒. 70种材料的系统阵列可以在一周内完成.
“这些优势使它成为不可缺少的发现工具,米勒女士说, 谁的工作背景包括激光, 材料, 和电催化作用. “你经常会遇到懂激光和材料的人, 或者是电催化和材料, 但你很少能找到同时精通这三方面的人.”
她说, “这就是促使我们写这篇论文的原因, because the Müller group can bring together the perspectives of all three fields.”
催化剂如何应对气候变化
在加州理工学院当科学家的时候, Müller pioneered an adaption of the laser-in-liquids technique to prepare nonprecious water-splitting electrocatalysts that liberate oxygen from water to produce clean hydrogen. 在澳门威尼斯人网上赌场, the Müller group expands on her expertise to study laser-made electrocatalysts as a way to turn climate-damaging carbon dioxide (CO2) into a closed cycle of useful liquid fuels, 比如甲醇或乙醇.
“If you were to burn these fuels again, you make CO2 again, so you go round and round. 碳总是在循环中, 也不会加剧气候变化,勒女士说. “要做到这一点，我们需要催化剂, 目前还没有人知道这些催化剂是什么——什么会起作用，为什么会起作用, 以及为什么其他催化剂不起作用.”
Hence her interest in using pulsed-laser-in-liquid synthesis to accelerate the process. “It is hugely important because we can’t just sit and hope for the best with climate change; we need to work on successor technologies now,她说。.
到目前为止，脉冲激光在液体中的合成只有有限的商业用途. The start-up cost of investing in laser technology is a stumbling block for many companies, Muller说. “But that will change as this method gets more and more traction,” she believes.
Thanks to Müller’s lab, pulsed-laser-in-liquids synthesis is certainly getting more attention. 三周内, 他们的论文被下载了超过1次，成为了一种催化剂,500倍.
阅读更多
新型啁啾脉冲挑战“传统智慧”Rochester researchers have advanced a groundbreaking technique first pioneered 在 University’s Laboratory for Laser Energetics to produce chirped pulses with relatively low-quality, 便宜的设备.
激光蚀刻出一个“完美的”太阳能吸收器The 澳门威尼斯人网上赌场 research lab that recently used lasers to create unsinkable metal structures has now demonstrated how the same technology could be used to create highly efficient solar power generators.
罗彻斯特在激光科学上的突破获得诺贝尔奖澳门威尼斯人网上赌场 graduate Donna Strickland ’89 (PhD) and former optics faculty member Gérard Mourou shared the 2018 Nobel Prize in Physics for work they undertook 在 Laboratory for Laser Energetics.
