Isotropic Hedgehog-Shaped-TiO2/Functional-Multiwall-Carbon-Nanotube Micromotors with Phototactic Motility in Fuel-Free Environments
Isotropic Hedgehog-Shaped-TiO2/Functional-Multiwall-Carbon-Nanotube Micromotors with Phototactic Motility in Fuel-Free Environments
复制标题
在无燃料环境中具有趋光性的各向同性刺猬型二氧化钛/功能性多壁碳纳米管微电机
DOI：
10.1021/acsami.0c19606
复制
发表时间：
2021-01-21
影响因子：
9.5
通讯作者：
Hu, Chengzhi
中科院分区：
文献类型：
--
作者：
Jiang, Huaide;He, Xiaoli;Hu, Chengzhi
响应特定信号的定向运动对于微/纳米电机在精确货物运输、避障、集体控制和复杂操纵中至关重要。在这项工作中，开发了一种由刺猬形状的TiO2和功能性多壁碳纳米管（Hs-TiO2@FCNTs）制成的各向同性光驱动微电机。 FCNT与Hs-TiO2紧密缠绕，并在Hs-TiO2表面形成紧密结合的基体，有利于电子从Hs-TiO2转移到FCNT。由于Hs-TiO2的高氧化还原电位、添加FCNT带来的优异的电子空穴分离效率以及微电机的各向同性形貌，这些Hs-TiO2@FCNT微电机在紫外光的单向照射下表现出趋光性和无燃料推进力。这是首次展示由自电泳驱动的各向同性微电机。 Hs-TiO2@FCNT微电机的各向同性使其不受旋转布朗扩散和局部流动的影响，表现出优异的方向性。我们的微电机的运动方向可以通过光精确调节，在 160 mW/cm(2) 紫外光照射下可实现 8.9 μ m/s 的速度。我们的微电机的概念验证应用展示了亚甲基蓝的光降解和聚苯乙烯珠的主动运输。 Hs-TiO2@FCNT微电机的各向同性设计具有增强的光催化性能，为解决当前非对称光驱动微电机中方向控制和化学燃料的局限性提供了一种新的范例。
Directional motion in response to specific signals is critically important for micro/nanomotors in precise cargo transport, obstacle avoidance, collective control, and complex maneuvers. In this work, a kind of isotropic light-driven micromotor that is made of hedgehog-shaped TiO2 and functional multiwall carbon nanotubes (Hs-TiO2@FCNTs) has been developed. The FCNTs are closely entangled with Hs-TiO2 and form a close-knit matrix on the surface of Hs-TiO2, which facilitates the transfer of electrons from Hs-TiO2 to FCNTs. Due to the high redox potential of Hs-TiO2, excellent electron-hole separation efficiency by the addition of FCNTs, and isotropic morphology of the micromotor, these Hs-TiO2@FCNT micromotors show phototactic and fuel-free propulsion under unidirectional irradiation of UV light. It is the first time to demonstrate isotropic micromotors that are propelled by self-electrophoresis. The isotropy of Hs-TiO2@FCNT micromotors makes them immune to the rotational Brownian diffusion and local flows, exhibiting superior directionality. The motion direction of our micromotors can be precisely tuned by light and a velocity of 8.9 mu m/s is achieved under 160 mW/cm(2) UV light illumination. Photodegradation of methylene blue and active transportation of polystyrene beads are demonstrated for a proof-of-concept application of our micromotors. The isotropic design of the Hs-TiO2@FCNT micromotors with enhanced photocatalytic properties unfolds a new paradigm for addressing the limitations of directionality control and chemical fuels in the current asymmetric light-driven micromotors.