Superhydrophobic graphene nanowalls for electromagnetic interference shielding and infrared photodetection via a two-step transfer method

Abstract

The growing need for flexible electronic devices has triggered substantial research efforts toward multifunctional surfaces. Herein, flexible and superhydrophobic surfaces based on micro-nanoscale two-tier structures were prepared by combining graphene nanowalls (GNWs) with UV-curable adhesive polymer using a two-step transfer method. These GNWs/UVA surfaces show excellent superhydrophobic properties with a water contact angle (CA) above 170° and a rolling angle (RA) below 5°. The superhydrophobic properties are retained with extreme liquid repellency even after thousand times of bending. The surfaces are highly conductive (conductivity > 3000 S/m) and provide excellent electromagnetic interference (EMI) shielding effect over the range of 8.2–12.4 GHz (X-band). Moreover, the surfaces exhibit high average infrared (IR) absorption up to 85 % in the range of 2–20 μm, indicating good performance in IR shielding. Furthermore, a long-wave IR photodetector with flexible hydrophobic GNWs/UVA was prepared, which has a responsivity of 28 μA/W at room temperature. The IR photodetector also has good water resistance stability. The methodology reported here provides a new route to fabricate micro-nano structures for multifunctional superhydrophobic surfaces. It has great potential for myriad applications in commercially viable flexible electronics, EMI protection, and IR photodetection.