Fabrication of a superhydrophobic porous electrode with voltage-induced anti-fogging properties†

The design of stable superhydrophobic surfaces with anti-fogging properties activated by an applied voltage represents one of the most effective methods in the surface and interface sciences. In particular, a flexible three-dimensional (3D) porous electrode capable of resisting high humidity environments (fog) is expected to have a broader range of applications in smart wearable devices. Hence, a superhydrophobic and porous ODT/MWCNTs/MeS electrode has been proposed and investigated for its ability to respond stably under a specific applied voltage. The long alkyl chains of 1-octadecanethiol (ODT) are triggered by the applied voltage to induce chain stretching. The static contact angle of water on the 3D porous electrode is 158.7° at a supply voltage of 0 V, increasing to 162.1° when the voltage is 10 V. The numerous long alkyl chains on the MWCNT coating have been shown to be effective in trapping fog, which can accumulate on the superhydrophobic electrodes to form a liquid film. The C–V curve of the superhydrophobic electrodes remains almost unaffected at a supply voltage of 10 V, even under continuous fog spray. Moreover, the i–t curve demonstrates that the continuous fog has minimal impact on the sensitivity and stability of ODT/MWCNTs/MeS electrodes at 10 V. In conclusion, this superhydrophobic and porous electrode, as a smart wearable sensor, can be activated by a supply voltage to achieve a stable response in a humid environment.