Li Cheng-Ai, Ko Boemjin, Park Kwang-Hyun, Ahn Jae-Gyu, Park Taeyoung, Lee Dong-Ju, Song Sung-Ho
Division of Advanced Materials Engineering, Center for Advanced Powder Materials and Parts, Kongju National University, Cheonan 32588, Republic of Korea.
Department of Advanced Materials Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju 28644, Republic of Korea.
Materials (Basel). 2023 Dec 21;17(1):41. doi: 10.3390/ma17010041.
It is difficult to obtain ultrathin two-dimensional (2D) tungsten trioxide (WO) nanosheets through direct exfoliation from bulk WO in solution due to the strong bonding between interlayers. Herein, WO nanosheets with controllable sizes were synthesized via K intercalation and the exfoliation of WO powder using sonication and temperature. Because of the intercalation and expansion in the interlayer distance, the intercalated WO could be successfully exfoliated to produce a large quantity of individual 2D WO nanosheets in -methyl-2-pyrrolidone under sonication. The exfoliated ultrathin WO nanosheets exhibited better electrochromic performance in an electrochromic device than WO powder and exfoliated WO without intercalation. In particular, the prepared small WO nanosheets exhibited excellent electrochromic properties with a large optical modulation of 41.78% at 700 nm and fast switching behavior times of 9.2 s for bleaching and 10.5 s for coloring. Furthermore, after 1000 cycles, the small WO nanosheets still maintained 86% of their initial performance.
由于层间存在强键合作用，通过在溶液中直接从块状三氧化钨（WO₃）剥离来获得超薄二维（2D）三氧化钨纳米片是很困难的。在此，通过钾离子插层以及利用超声和温度对WO₃粉末进行剥离，合成了尺寸可控的WO₃纳米片。由于层间距离的插层和扩大，插层后的WO₃在超声作用下能够在N-甲基-2-吡咯烷酮中成功剥离，从而产生大量单个的2D WO₃纳米片。与WO₃粉末和未插层的剥离WO₃相比，剥离后的超薄WO₃纳米片在电致变色器件中表现出更好的电致变色性能。特别是，制备的小尺寸WO₃纳米片表现出优异的电致变色性能，在700 nm处具有41.78%的大光学调制，漂白的快速切换行为时间为9.2 s，着色的快速切换行为时间为10.5 s。此外，经过1000次循环后，小尺寸WO₃纳米片仍保持其初始性能的86%。
