Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering , Beijing Institute of Technology , Beijing 100081 , China.
Department of Chemistry , National University of Singapore , Singapore 119077 , Singapore.
ACS Appl Mater Interfaces. 2018 Aug 29;10(34):28627-28634. doi: 10.1021/acsami.8b08908. Epub 2018 Aug 15.
Preparation of ultrafine highly dispersed VO(M) nanoparticles that are essential materials to fabricate thermochromic flexible films remains a challenge, preventing effective use of their promising properties. Here, we report an original hydrothermal approach by controlling oxidizing atmosphere of reaction with hydrogen peroxide to prepare ultrafine VO(M) nanoparticles free from annealing. Hydrogen peroxide is separated from precursor solution in a reactor, which creates a moderate oxygenation environment, enabling the formation of stoichiometric VO(M) nanoparticles. The obtained VO(M) nanoparticles are well-dispersed, highly uniform, and single-phase, with an average particle size ∼30 nm. The flexible thermochromic films fabricated with the VO(M) nanoparticles exhibit excellent thermochromic performance with a solar modulation efficiency of 12.34% and luminous transmittance of 54.26%. While the films prepared with annealed nanoparticles show reduced transmittance due to light scattering of the large size particles resulting from agglomeration and growth during annealing. This work demonstrates a promising technique to realize moderate oxidizing atmosphere by hydrothermal process for preparing well-dispersed stoichiometric nano-oxides.
制备超细微高分散 VO(M) 纳米粒子是制备热致变色柔性薄膜的关键材料，但目前仍然具有挑战性，这阻碍了其潜在性能的有效利用。在这里，我们通过控制反应中的氧化气氛（使用过氧化氢），提出了一种原创的水热方法，制备了无需退火的超细微 VO(M) 纳米粒子。过氧化氢在反应器中与前驱体溶液分离，创造了一个适度的氧化环境，从而形成了化学计量的 VO(M) 纳米粒子。所获得的 VO(M) 纳米粒子具有良好的分散性、高度的均匀性和单相性，平均粒径约为 30nm。用 VO(M) 纳米粒子制备的柔性热致变色薄膜具有优异的热致变色性能，太阳能调制效率为 12.34%，可见光透过率为 54.26%。而用退火纳米粒子制备的薄膜由于在退火过程中团聚和生长导致粒径增大而产生的光散射，透光率降低。这项工作展示了一种通过水热法实现适度氧化气氛的有前途的技术，用于制备分散良好的化学计量纳米氧化物。
