Enhanced moisture-enabled electricity generation through carbon dot surface functionalization using strong ionizing organic acid

Abstract

Moisture-enabled electricity generation (MEG) is regarded as a highly promising technique for sustainable electric power. Carbon dots (CDs) are shown to have great promise in MEG devices due to their low-cost fabrication and tunable surface groups, but their potential in MEG devices has not been fully exploited. Herein, we demonstrate a simple and effective method to significantly enhance the output of a CD-based MEG device based on CD surface functionalization using a strong ionizing organic acid. Compared to a bare CD-based MEG device, a voltage output of a 1,5-naphthalenedisulfonic acid (1,5-NDSA) functionalized CD (S-CD)-based MEG device shows great performance, with a voltage that reaches up to 380 mV. To the best of our knowledge, this is the highest value reported for a CD-based MEG device to date. Our results show that the large number of protons produced by the S-CDs facilitates the creation of a strong proton gradient and improves ionic conductivity, thus leading to an enhancement in the electricity output. By simply connecting MEG devices in series, the overall assembled device can generate enough electricity to power an electronic calculator. Furthermore, the output of the as-prepared device can be greatly enhanced under the flow of moist air, which is expected to make it useful for windy and high humidity areas.