聚氧甲集成高氧化物亚-1纳米纳米线
Junli Liu1, Yuqi Li2, Zhao Chen2
1Engineering Research Center of Advanced Rare Earth Materials, Department of Chemistry, Tsinghua University, Beijing100084, China.
Journal of the American Chemical Society
|December 8, 2022
概括
研究人员开发了一种新方法,使用聚氧金属制造亚-1纳米高氧化物 (HEO) 纳米线. 这些HEO纳米线作为离子电池的阳极表现出色,表现出增强的稳定性和容量.
科学领域:
- 材料科学
- 纳米技术
- 电化学
背景情况:
- 高氧化物 (HEO) 具有独特的特性,但控制它们的纳米尺寸仍然具有挑战性.
- 低于1纳米尺度的材料提供了增强的性能,但很难通过精确的控制来合成.
研究的目的:
- 为合成具有可控制组成和形态的低于1纳米高氧化物纳米线 (HEO-SNW) 开发一种多功能策略.
- 研究这些新型HEO材料在离子电池中的应用.
主要方法:
- 使用聚氧金属 (POM) 集群作为模板,将多种不可混合的金属氧化物纳入亚-1nm纳米线.
- 在温和条件下 (140°C) 合成HEO-POM SNWs,可灵活调节金属氧化物和POM物种.
- 评估了HEO-POM SNW作为Na-ion电池中的阳极的电化学性能.
主要成果:
- 在亚-1纳米尺度上成功合成了多种高度排序的HEO-POM SNW.
- 在离子电池中表现出优异的电化学特性,性能随着金属氧化物物种的增加而得到改善.
- 在10°C下5000次循环后保持约92%的容量,实现了极好的稳定性和长周期寿命.
结论:
- 开发的POM模板策略可以轻松和可控地合成1nm以下的HEOs.
- 作为离子电池的高性能阳极材料,HEO-POM SNW具有显著的潜力.
- 这项工作为在温和条件下设计和制备纳米级HEO提供了新的见解.
相关概念视频
02:58Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
02:21Oxidation of Alkenes: Syn Dihydroxylation with Potassium Permanganate
Alkenes can be dihydroxylated using potassium permanganate. The method encompasses the reaction of an alkene with a cold, dilute solution of potassium permanganate under basic conditions to form a cis-diol along with a brown precipitate of manganese dioxide.
02:04Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
01:23Properties of Organometallic Compounds
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.