What are the Tower's method products: Metal-hydroxides or metal-glycerolates?
What are the Tower's method products: Metal-hydroxides or metal-glycerolates?
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塔的方法产品有哪些：金属氢氧化物或金属甘油盐？
DOI：
10.1016/j.matchar.2022.112636
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发表时间：
2023
影响因子：
4.7
通讯作者：
Shahbazian-Yassar, Reza
中科院分区：
文献类型：
--
作者：
Gonçalves, Josué M.;Lima, Irlan S.;Phakatkar, Abhijit H.;Pereira, Rafael S.;Martins, Paulo R.;Araki, Koiti;Angnes, Lúcio;Shahbazian-Yassar, Reza
长期以来，人们一直认为胶体氢氧化镍纳米颗粒是通过镍盐、甘油和氢氧化钾的反应（称为塔法）产生的。在目前的工作中，我们挑战这一信念，并揭示了错误的原因，在识别的镍产品生产的塔的方法。我们建议，镍基前体配合物的塔法反应的主要产品，这些前体进行过渡到层状镍甘油衍生物热处理后。我们证明了Ni 2+与不同类型的O-供体配体（甘油、甘油酸根离子、乙酸根离子和/或OH−）配位形成Ni络合物前体。利用原位透射电子显微镜，我们发现镍基前驱体配合物可以在电子束照射下转化为镍纳米颗粒，但没有发现氢氧化镍纳米颗粒形成的证据。氢氧化镍纳米颗粒只有在Ni-甘油酸盐前驱体与碱性水溶液进一步反应后才形成。这些新发现揭示了Ni 2+与甘油在塔式反应中反应所得到的金属衍生物的性质，为电池、超级电容器、电催化剂和电化学传感器等电极材料的设计提供了更坚实的基础。
It has been long believed that colloidal nickel hydroxide nanoparticles are produced by the reaction of nickel salts, glycerol and potassium hydroxide known as the Tower method. In the present work, we challenge this belief and reveal the reasons for error in identification of nickel products produced by the Tower method. We propose that Ni-based precursor complexes are the primary products of the Tower method reaction, and these precursors undergo transition to layered Ni-glycerolate derivatives upon thermal treatment. We demonstrated the presence of Ni2+coordinated to different types of O-donor ligands (glycerol, glycerolate ion, acetate ion and/or OH−) forming Ni-complex precursors. Usingin-situtransmission electron microscopy, we showed that Ni-based precursor complexes can be converted to nickel nanoparticles upon exposure to electron beam, but no evidence of nickel hydroxide nanoparticle formation was found. The nickel hydroxide nanoparticles are only formed upon further reaction of Ni-glycerolate precursors with an aqueous alkaline solution. Those new findings shed light on the nature of the metal derivatives obtained by the reaction of Ni2+and glycerol in the Tower method and provide more solid foundation to design electrode materials for batteries, supercapacitors, electrocatalysts and electrochemical sensors.