Lambregts Sander F H, de Kort Laura M, Winkelmann Frederik, Felderhoff Michael, Ngene Peter, van Eck Ernst R H, Kentgens Arno P M
Magnetic Resonance Research Center, Institute for Molecules and Materials, Radboud University, 6525AJ, Nijmegen, The Netherlands.
Materials Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, 3584CG, Utrecht, The Netherlands.
J Phys Chem C Nanomater Interfaces. 2024 Jul 17;128(29):12186-12193. doi: 10.1021/acs.jpcc.4c02667. eCollection 2024 Jul 25.
Nanocomposites of complex metal hydrides and oxides are promising solid state electrolytes. The interaction of the metal hydride with the oxide results in a highly conducting interface layer. Up until now it has been assumed that the interface chemistry is independent of the nanoconfinement method. Using Si solid state NMR and LiBH/SiO as a model system, we show that the silica surface chemistry differs for nanocomposites prepared via melt infiltration or ball milling. After melt infiltration, a Si···H···BH complex is present on the interface, together with silanol and siloxane groups. However, after ball milling, the silica surface consists of Si- H sites, and silanol and siloxane groups. We propose that this change is related to a redistribution of silanol groups on the silica surface during ball milling, where free silanol groups are converted to mutually hydrogen-bonded silanol groups. The results presented here help to explain the difference in ionic conductivity between nanocomposites prepared via ball milling and melt infiltration.
复杂金属氢化物与氧化物的纳米复合材料是很有前景的固态电解质。金属氢化物与氧化物之间的相互作用会形成高导电界面层。到目前为止，人们一直认为界面化学与纳米限域方法无关。我们以硅固态核磁共振（Si solid state NMR）和LiBH/SiO作为模型体系，表明通过熔体渗透或球磨制备的纳米复合材料的二氧化硅表面化学性质有所不同。熔体渗透后，界面上存在Si···H···BH络合物以及硅醇和硅氧烷基团。然而，球磨后，二氧化硅表面由Si-H位点以及硅醇和硅氧烷基团组成。我们认为这种变化与球磨过程中二氧化硅表面硅醇基团的重新分布有关，在此过程中，游离硅醇基团转变为相互氢键连接的硅醇基团。此处给出的结果有助于解释通过球磨和熔体渗透制备的纳米复合材料之间离子电导率的差异。
