Laser‐Induced Graphene in Controlled Atmospheres: From Superhydrophilic to Superhydrophobic Surfaces

Abstract

The modification of graphene-based materials is an important topic in the field of materials research. This study aims to expand the range of properties for laser-induced graphene (LIG), specifically to tune the hydrophobicity and hydrophilicity of the LIG surfaces. While LIG is normally prepared in the air, here, using selected gas atmospheres, a large change in the water contact angle on the as-prepared LIG surfaces has been observed, from 0° (superhydrophilic) when using O or air, to >150° (superhydrophobic) when using Ar or H . Characterization of the newly derived surfaces shows that the different wetting properties are due to the surface morphology and chemical composition of the LIG. Applications of the superhydrophobic LIG are shown in oil/water separation as well as anti-icing surfaces, while the versatility of the controlled atmosphere chamber fabrication method is demonstrated through the improved microsupercapacitor performance generated from LIG films prepared in an O atmosphere.

Direct Semiconductor Laser Writing of Few‐Layer Graphene Polyhedra Networks for Flexible Solid‐State Supercapacitor

“…For example, the grating of CN moiety may not only vary the Femi energy level of carbon substrate, but may induce faradaic redox reactions with the electrolytes. [23][24][25] This difference should be attributed to relative high oxygen content in our carbon polyhedra networks. Compared to the initial PI sheets, the atomic concentration of carbon rises from 76 at % (calculated from the monomer unit of PI) to 83 at% after laser writing process.…”

“…[21] Toward the application as electrode materials for supercapacitors, it is pivotal to uncover the chemical environments of the heteroatoms in the carbon matrix. According to the previous reports, laser directly writing polyimide sheets are hydrophobic, and even superhydrophobic under the ambient condition or controllable atmosphere, [11,23] resulting in plasma or strong acid treatment is generally needed to improve the wettability of surface. Figure 6a supplied core-level XPS survey profile of the sample.…”

Laser‐Induced Freestanding Graphene Papers: A New Route of Scalable Fabrication with Tunable Morphologies and Properties for Multifunctional Devices and Structures

“…It is suggested that argon could further reduce the amount of polar CO and CO bonds in LIGP. Free from unwanted substrates, the hydrophobic LIGP is highly advantageous without redundant treatments such as thin film transfer and generation of holes on substrates …”

UV Laser‐Induced Polyimide‐to‐Graphene Conversion: Modeling, Fabrication, and Application

“…Laser manufacturing has become increasingly popular in material fabrication due to its high throughput and patterning capability. Recently, it was demonstrated that a commercial CO 2 infrared laser scriber can be used to in situ form and pattern 3D porous graphene on polyimide (PI), cloth, paper, and food under ambient conditions. In comparison to the laser‐reduced graphene method, which uses a laser to reduce graphene oxide (GO) films to graphene, the new laser‐induced graphene (LIG) method avoids the use of GO precursors and directly exploits the substrate materials as a carbon source, which greatly simplifies the fabrication process and reduces the cost .…”