Han Do Hyung, Park Hyunsu, Goto Tomoyo, Seo Yeongjun, Kondo Yoshifumi, Cho Sunghun, Sekino Tohru
SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
Institute for Advanced Co-Creation Studies, Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
ACS Omega. 2024 Jul 22;9(30):33293-33300. doi: 10.1021/acsomega.4c05470. eCollection 2024 Jul 30.
Layered alkali titanates of the lepidocrocite type are gaining enormous interest in various fields owing to their unique properties. These materials are mainly synthesized through a hydrothermal alkali treatment. However, this method uses a highly concentrated alkali solution, which has high environmental impacts and is therefore unsuitable for mass synthesis. Herein, we propose an efficient method for the large-scale synthesis of layered sodium titanate structures (Na H TiO) using a recently reported bottom-up chemical process. The effects of the Na:Ti molar ratio in the peroxo-titanium complex ion precursor on the products are investigated through stoichiometric calculations for a molar ratio range of 10:1-1:1. The optimal ratio for the complete ionization of TiH (which is the starting material) to form the peroxo-titanium complex ion is found to be 1.1:1. The amount of alkali raw material required is 99.6% lower than that required in the traditional hydrothermal method. The crystal structures and morphologies of the samples are almost identical regardless of the Na:Ti molar ratio. The precursor-derived peroxo bonds narrow the energy band gaps of the layered titanates even when the amount of titanium ions dissolved in the precursor increases. The proposed method is not only an efficient synthetic route for mass production but also has potential applications in the development of photofunctional materials.
纤铁矿型层状碱金属钛酸盐因其独特的性能而在各个领域引起了极大的关注。这些材料主要通过水热碱处理合成。然而，这种方法使用高浓度的碱溶液，对环境影响很大，因此不适合大规模合成。在此，我们提出了一种利用最近报道的自下而上化学过程大规模合成层状钛酸钠结构（NaHTiO）的有效方法。通过对10:1 - 1:1摩尔比范围的化学计量计算，研究了过氧钛络合离子前驱体中Na:Ti摩尔比对产物的影响。发现TiH（起始原料）完全电离形成过氧钛络合离子的最佳比例为1.1:1。所需碱原料的量比传统水热法低99.6%。无论Na:Ti摩尔比如何，样品的晶体结构和形态几乎相同。即使前驱体中溶解的钛离子量增加，前驱体衍生的过氧键也会使层状钛酸盐的能带隙变窄。所提出的方法不仅是大规模生产的有效合成路线，而且在光功能材料的开发中具有潜在应用。
