Abstract
Biomass-derived activated carbon (Bio-AC) was prepared by catalytic activation of corn stover followed by milling and surface modification. The prepared Bio-AC was coated onto a fibrous material to fabricate the biomass-derived moisture diffusion energy harvester (Bio-MDEH), which generates electricity from the flow of ions in moisture that diffuse along the interface of conductive carbon particles. The performance of this device was evaluated by measuring open-circuit voltage (Voc) and short-circuit current (Isc). The maximum performance of 926.2 mV and 37.75 μA, which is 4.6-fold of carbon black MDEH, was achieved using KOH-catalyzed activated carbon. Development of mesopore structure, introduction of hydrophilicity, and improvement of electrical conductivity induced from catalytic activation contributed to the improvement of MDEH performance. Several Bio-MDEHs connected in series or parallel reliably generated 1.8 V and 214 μA of electricity and successfully lit a single light-emitting diode. A Bio-MDEH conduction model has also been proposed. Activated carbons have relatively large particle sizes due to their abundant mesoporous structures, which leads to high performance but low cross-connection between activated carbon particles. Thus, they need to be interconnected via carbon black, which acts as a cross-linking conductor. This paper showed that high energy harvesting efficiency of water diffusion energy harvesters can be achieved through the use of biomass-derived carbon materials. We hope that this study will contribute to the development of water diffusion energy harvesters into practical applications as sustainable solutions to future energy crises.
•Moisture diffusion energy harvester was fabricated with biomass-derived activated carbon.•Carbon black acts as a cross-linking conductor in energy harvester.•Maximum performance of energy harvester was measured to 926.2 mV and 37.75 μA.•LED was successfully turned on from several energy harvesters in series/parallel.