Abstract Layered double hydroxides (LDHs) have attracted attention as green materials due to their catalytic ability in benign aqueous solvents. We here demonstrate the synthesis of colloidal Co–Al LDH nanoclusters with an average size of <10 nm via a facile liquid-phase reaction for the enhancement of the catalytic activity. To the best of our knowledge, the present LDH is the smallest Co–Al LDH with an extremely large surface area and stability in an aqueous solvent, forming a stable and concentrated colloidal solution as high as 40 g/L. We investigated the formation mechanism, and the catalytic activity of Co–Al LDH nanoclusters. The Co–Al LDH nanoclusters showed 47 times higher rate of the reduction of dye molecules in the aqueous media than standard Co–Al LDH particles with a micrometer size. LDH nanoclusters demonstrated here are promising green nanocatalysts for the aqueous reaction processes.

中文翻译：

---

在水介质中合成作为还原纳米催化剂的 Co-Al 层状双氢氧化物纳米团簇

摘要 层状双氢氧化物（LDHs）因其在良性水性溶剂中的催化能力而作为绿色材料备受关注。我们在这里展示了通过简便的液相反应合成平均尺寸 <10 nm 的胶体 Co-Al LDH 纳米团簇，以提高催化活性。据我们所知，目前的 LDH 是最小的 Co-Al LDH，具有极大的表面积和在水性溶剂中的稳定性，可形成高达 40 g/L 的稳定且浓缩的胶体溶液。我们研究了 Co-Al LDH 纳米团簇的形成机制和催化活性。与微米尺寸的标准 Co-Al LDH 颗粒相比，Co-Al LDH 纳米团簇在水性介质中的染料分子还原率高 47 倍。