Confined-space synthesis of nanostructured anatase, directed by genetically engineered living organisms for lithium-ion batteries.
Confined-space synthesis of nanostructured anatase, directed by genetically engineered living organisms for lithium-ion batteries.
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DOI：
10.1039/c6sc02311h
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发表时间：
2016-10-01
期刊：
影响因子：
8.4
通讯作者：
Fu Z
中科院分区：
文献类型：
--
作者：
Ping H;Xie H;Xiang M;Su BL;Wang Y;Zhang J;Zhang F;Fu Z
基因工程生物体指导合成具有纳米颗粒、介孔结构和碳包覆特性的纳米结构锂离子电池，显示出优异的锂储存性能。自然界中生物矿物的形成过程是在有限空间中受生物分子作用的时空调控。通过考虑有限空间以及生物分子来合理地设计矿化系统可能是非常有成效的。“细菌细胞表面展示”的实验室技术是一个理想的平台，主机催化活性蛋白质在三维有限的空间。在本研究中，为了调节纳米结构的二氧化钛纳米粒子的合成，通过基因操作在大肠杆菌表面展示硅亲蛋白的重复片段。展示的蛋白质与钛源静电相互作用，并通过细胞表面上的氢键相互作用催化二氧化钛前体的水解。在随后的煅烧过程中，基因修饰的细胞不仅作为一个框架，以生产棒状TiO 2组装的纳米粒子，但也提供了原位碳源。通过改变蛋白质片段的串联重复序列的数量来控制纳米颗粒的大小。所制备的TiO 2纳米晶具有纳米尺寸的微晶、介孔结构和碳包覆等独特的性能。当作为锂离子电池的阳极电极进行测试时，它表现出优异的锂存储性能。碳包覆的碳负极在1C电流速率下循环200次后的比容量为207 mA h g-1，在10 C较高电流速率下循环5000次后的超长循环寿命为149 mA h g-1。这种生物过程启发的方法可能有助于扩大纳米生物矿物的范围和影响。
Genetically engineered living organisms direct the synthesis of nanostructured anatase with nanoparticle, mesoporous structure and carbon coating characteristics which shows excellent lithium storage performance. Biomineral formation processes in nature are temporally and spatially regulated under the functions of biomolecules in a confined space. It is potentially very productive to rationally design a mineralized system by taking into account confined space as well as biomolecules. The laboratory technique of “bacterial cell surface display” is an ideal platform to host catalytically active proteins in a three-dimensionally confined space. In the present study, aiming to regulate the synthesis of nanostructured TiO2 anatase, repeating segments of silaffin were displayed on Escherichia coli surfaces through genetic manipulation. The displayed protein electrostatically interacted with a titanium source and catalyzed the hydrolysis of titanium dioxide precursors through hydrogen bonding interactions on the cell surface. In the subsequent calcination process, the genetically modified cells not only served as a framework for producing rod-shaped TiO2 assembled by nanoparticles, but also provided a carbon source in situ. The size of nanoparticles was controlled by changing the number of tandem repeats of the protein segment. The as prepared TiO2 anatase exhibited unique characteristics including nanosized anatase crystals, mesoporous structure and carbon coating. When tested as the anode electrode of a lithium-ion battery, it showed excellent lithium storage performance. The carbon coated anatase anode shows a higher specific capacity of 207 mA h g–1 after 200 cycles at a current rate of 1C and an ultra-long cycling lifetime of 5000 cycles with an outstanding retention capacity of 149 mA h g–1 at a higher rate of 10C. This bioprocess-inspired approach may help broaden the scope and impact of nanosized biominerals.