Despite increasingly intensive research into catalytic hollow nanoreactors, most of the work has focused on the enclosed cavity structure, and attempts to use the open-mouthed cavity have not been made so far, most likely due to the lack of methodologies for producing and functionalizing such a structure. This paper reports a synthetic strategy toward open-mouthed cavity-based nanoreactors, which renders the SiO₂ nanosphere with a concave surface and also immobilizes catalytic nanocrystals (NCs) specifically inside the concave region. By putting the Janus silica-encapsulated manganese oxide (MnO) nanoparticle, with its highly off-centered [email protected] structure, through the thermal hollow-conversion process, the edge-touching MnO nanoparticle was transformed into a hollow hemispherical manganese silicate layer with an opening to the outside, thus producing the bitten apple-like structure, conc-(Ni/HMS)@SiO₂, with an open-mouthed cavity on the SiO₂ nanosphere. The galvanic replacement reaction occurring on the manganese-silicate layer of the conc-(Ni/HMS)@SiO₂ afforded the site-specific immobilization of catalytic Pt NCs on the preformed concave interior surface, signifying the possible postsynthetic functionalization of an open-mouthed cavity which could be adapted for the development of a nanoreactor system. The newly developed nanoreactor, [email protected]conc-SiO₂, carrying tiny catalytic Pt NCs inside the semiexposed and also semiprotected pocket-like space, exhibited an increased reaction rate and a more extended range of applicable substrates in catalyzing the reduction of nitroarene compounds, compared with the enclosed cavity-based analogue, while preserving the high immobilization stability of Pt nanocatalysts during the recycling process.

中文翻译：

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具有功能化的开口腔的凹形二氧化硅纳米球，作为高活性和耐用的催化纳米反应器

尽管对催化中空纳米反应器的研究日益深入，但大部分工作都集中在封闭的腔体结构上，到目前为止，尚未尝试使用开口腔体，这很可能是由于缺乏生产和功能化此类腔体的方法。结构。本文报告了一种开放策略的基于腔的纳米反应器的合成策略，该方法可产生SiO ₂具有凹面的纳米球，并且还可以将催化纳米晶体（NCs）固定在凹区内部。通过将Janus二氧化硅包裹的氧化锰（MnO）纳米颗粒以偏心的[受电子邮件保护]结构，通过热中空转化工艺，将触边的MnO纳米颗粒转变为空心的半球形硅酸锰层。一个向外的开口，从而产生咬合的苹果状结构，浓-（Ni / HMS）@SiO ₂，在SiO ₂纳米球上有一个开口的空腔。在浓-（Ni / HMS）@SiO ₂的硅酸锰层上发生的电化学置换反应提供了在预先形成的凹形内表面上将催化Pt NCs固定在位的方法，这表明开口腔可能在合成后进行了功能化，该功能可用于开发纳米​​反应器系统。新开发的纳米反应器，[电子邮件保护]浓-SiO ₂，携带细小催化的Pt纳米晶内的semiexposed并且还半保护袋状空间，表现出增加的反应速率和在催化硝基芳烃化合物的还原更扩展范围适用基材的与封闭的基于腔的类似物相比，同时在回收过程中保持了Pt纳米催化剂的高固定化稳定性。