摘要
Ultrathin two-dimensional(2 D)porous nanosheets are one of the most promising nanomaterials in various applications,whereas their synthesis is still challenging.Herein,ultrathin 2 D amorphous TiO_(2)(a-TiO_(2))porous nanosheet aerogel is synthesized via a surfactant-free assembly process followed by low-temperature calcination.The co-existing O-O and-OH groups on the surface of TiO_(2)precursor break the 3 D spherical symmetry,and the hydrogen bonding among the TiO_(2)precursors is proposed as the main driving force guiding the 2 D assembly.The surfactant-free assembly endows the ultrathin a-TiO_(2)porous nanosheet with improved ionic and electronic conductivity.The porous structure provides high surface area and easy electrolyte penetration,accelerating the Li ion diffusion rate of the a-TiO_(2)porous nanosheet.Attributing to the above advantages,the obtained a-TiO_(2)porous nanosheets are one of the best anode materials for lithium-ion batteries,which is proved by the enhanced electrochemical performance.
超薄多孔纳米片是应用领域极有前途的纳米材料之一,但它的合成仍具有很大的挑战性.本文报道了一种无表面活性剂组装工艺,低温煅烧后合成超薄二维非晶a-TiO_(2)多孔纳米片的方法.TiO_(2)前驱体(PTA)表面共存的O-O和-OH基团打破了三维球对称,而-OH基团之间的强氢键引发了各向异性的二维纳米片组装,最终获得超薄的PTA多孔纳米片.所得超薄PTA多孔纳米片经250℃煅烧可成功转化为aTiO_(2)多孔纳米片.通过原位透射电镜观察PTA纳米粒子的组装过程,进一步验证了PTA之间的氢键作用是引导二维结构组装的主要驱动力.另外,无表面活性剂的组装过程,以及非晶态导致的大量阳离子缺陷,使a-TiO_(2)多孔纳米片具有较高的离子导电性和电子导电性,同时,多孔结构为a-TiO_(2)多孔纳米片提供了高表面积、高电解液浸润性,加速了锂离子扩散速率.由于上述优点,制备的a-TiO_(2)多孔纳米片在锂离子电池负极材料应用中表现出较好的性能,未来有望用于高性能锂离子电池.
作者
Yue Qi
Xinqian Zeng
Liangping Xiao
Xingyun Li
Honggang Liao
Qingchi Xu
Jun Xu
齐越;曾心倩;肖良平;李星云;廖洪钢;许清池;徐俊(Department of Physics,Research Institute for Biomimetics and Soft Matter,Fujian Provincial Key Laboratory for Soft Functional Materials,Xiamen University,Xiamen 361005,China;Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China;Department of Chemical Engineering and Materials Science,Stevens Institute of Technology,Hoboken,New Jersey,07030,USA;Shenzhen Research Institute of Xiamen University,Shenzhen 518057,China)
基金
financially supported by the National Natural Science Foundation of China(21771154)
Shenzhen Fundamental Research Programs(JCYJ20190809161013453)
the Fundamental Research Funds for the Central Universities(20720220031)
the 111 Project(B16029)。
