Flexible Leaf-Like Fuel Cell From Plasmonic Janus Nanosheet

The ability to design leaf-like fuel cells may enable artificial tree-like electricity generators to power home appliances. However, the existing fuel cells are typically rigid and heavy in 3D layout. Here, this study reports on a flexible, lightweight, and 2D leaf-like methanol fuel cell based on conductive sponge-supported plasmonic Janus nanosheet. The nanosheet is made from self-assembled gold nanocube (Au NC) arrays, followed by spiky growth at one side and approximate to 5 nm palladium coating. Such designed nanosheets can simultaneously offer three functionalities: high electrochemically active surface area, chemical catalysis, and plasmon enhancement. This study finds that light-enhanced electrochemical performance can be retained over 90% even when being bent or twisted. Further integration of the Janus nanosheets with highly conductive gold nanowire sponges allowed for fabricating a flexible leaf-like fuel cell with a thickness of 3 mm and a weight of 0.1 g. The flexible leaf can generate a power of 8.93 mW cm-2 under light irradiation with less than 10% performance deterioration even under 360 degrees twisting and 180 degrees bending. In a tree-like design, 95% power retention is achieved under natural omnidirectional light irradiation and wind-induced deformation.