Moist-electric films based on asymmetric distribution of sodium alginate oxygen-containing functional groups

Moist-electric generation as a green process of power generation can effectively solve energy and environmental problems. In order to improve the moist-electric properties of moist-electric generator (MEG), this study designed and prepared a sodium alginate (SA)/multi-walled carbon nanotube (MWCNT) bilayer film hygroscopic generator with an asymmetric distribution of oxygen-containing functional groups (asym-SCM) by simple freeze-drying and pressing. The relative ratios of carbon and oxygen in the system were adjusted by changing the ratios of SA/MWCNT, and the advantages of constructing an asymmetric distribution of oxygen-containing functional groups on the moist-electrical properties of the material were verified. The asym-SCM MEG is able to draw moisture from the environment, generating an open circuit voltage up to ca. 0.65 V at low humidity (ca. 40%) and generating power continuously for up to 650 min. At 90% humidity, the asym-SCM MEG can achieve an output voltage of ca. 0.78 V, well above the power generation performance of most biomass materials moist-electric studies in the current phase. This MEG is green, biocompatible, biodegradable, promising to be used as a self-powered device for flexible wearable, biomedical and other applications. [Display omitted] •The relative content of oxygen in the material was regulated by physical blends.•The asym-SCM MEG with continuous power generation was prepared by a physical method.•The effect of moisture flow rate on power generation performance was investigated.•5 asym-SCM MEGs in series can light up LED bulbs without capacitors.