Abstract

The rational design of nanomaterials with distinct exposed facets is of great importance for improving the physicochemical properties of these materials and for the study of structure–activity relationships. This work describes the first synthesis of lanthanum titanate (La₂Ti₂O₇, LTO) with dandelion-like nanostructures via the molten salt method. The lowest synthesis temperature of 700 °C is at least 200 °C lower than that required by other methods. The dandelion structure consists of well-crystallized LTO nanorods (NRs) with sizes of less than 100 nm in the radial direction and 300–500 nm in the axial direction, which is different from the widely accepted two-dimensional form. LaOCl microplates were formed as an intermediate substrate for LTO NR growth outwards to the basal surfaces of the LaOCl crystallites. DFT calculation results showed that the strong LiCl adsorption on the (100) surface led to distinct growth of the (100) and (020) planes, thus promoting the rod-like growth of LTO along the [010] axis. In addition, the photocatalytic performance of as-prepared LTO was evaluated by determining the degradation of rhodamine B. The results suggested that the as-prepared LTO could markedly enhance the photocatalytic activity as a result of the surface heterojunction of coexposed {100} and {002} facets in LTO NRs.

中文翻译：

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一步法合成蒲公英样钛酸镧纳米结构以增强光催化性能

摘要

合理设计具有不同暴露面的纳米材料对于改善这些材料的物理化学性质以及研究结构-活性关系非常重要。这项工作描述了钛酸镧（La ₂ Ti ₂ O ₇，LTO）通过熔融盐法具有类似蒲公英的纳米结构。最低合成温度为700°C，比其他方法所需的合成温度至少低200°C。蒲公英结构由结晶良好的LTO纳米棒（NRs）组成，其径向尺寸小于100 nm，轴向尺寸小于300-500 nm，这与公认的二维形式不同。LaOCl微板形成为LTO NR向外生长到LaOCl微晶基面的中间基质。DFT计算结果表明，在（100）表面上强烈的LiCl吸附导致（100）和（020）平面明显生长，从而促进了LTO沿[010]轴的棒状生长。此外，