writer：Lieshuang Zhong, Huan Chen, Lingmei Zhu, 等
keywords：liquid confined modification, gradient-Janus wettability, droplet manipulate, water harvesting, energy harvesting
source：期刊
Issue time：2024年

ACS Nano 2024, 18, 10279?10287，https://doi.org/10.1021/acsnano.4c01386 

Abstract：

Gradient-Janus wire (GJW) with a diameter of 0.3 mm has been fabricated

on a large scale through liquid confined modification, enabling the opposite conical wetting

phenomenon along the same orientation of the GJW, characterized by an increasing

superhydrophilic region and a decreasing hydrophobic region. This property allows the GJW

to exhibit controllable water hovering, transport, and pinning during fog harvesting, i.e., at a

large tilting angle α of 60° (mass increased with decreased α), the GJW can hover 0.6 mg of

harvested fogwater in 30 s, can transport 3 mg of fogwater along the gradient in 30 s at α =

4° (with maximal mass reaching up to 4.3 mg at α = ?10°), and finally, pin the water droplet

at the end of the GJW. Such ability generates an effective torque that serves as the driving

force for rotation. We designed a GJWs-wheel by radially arranging 60 GJWs together,

resulting in an extremely lightweight structure weighing only 1.9 g. The cumulative torque

generated during fog harvesting activates the rotation of the GJWs-wheel. When loaded with

a coil within a magnetic field, electricity is generated as output power peaks at around 0.25

μW while maintaining a high water harvesting efficiency averaging approximately 38 ± 2.12 mg/min. This finding is significant

as it provides valuable insights into designing materials capable of efficiently harnessing both energy and water resources.