The electric energy harvesting from natural water evaporation has attracted great attention in the sustainable development of societies. However, ultra-low short-circuit current extremely hinders its widespread deployment. Herein, we report...

Water evaporation-induced power generation technologies based on the interaction between water and nanomaterials have received wide attention over the years. Herein, a natural wood-based water evaporation-induced power generator (EIPG) via the surface carbonization technique under high-temperature hydrogen–oxygen flame was developed. The unique surface carbonization strategy made the internal layer (uncarbonized layer) maintain high hydrophilicity to satisfy the stable and continuous capillary flow for the transport of ions. The internal layer possessed a higher surface charge density, promoting the establishment of the electric double layer (EDL), which ensured high selectivity of the wood channels for positive ions. Meanwhile, the external carbonized layer could effectively adsorb positively charged ions through strong cation−π interactions to strengthen the EDL effect. The carbonized layer also provided an electrical charge transportation channel, lowering the resistance of the device. The device could continuously generate power with an open-circuit voltage (V oc) of ∼170 mV and a short-circuit current (I sc) of ∼730 nA over 24 h, exhibiting excellent stability. Moreover, a higher electric output was generated by the water EIPG through assembling several devices in series or parallel and applied successfully in charging capacitors and powering a commercial digital calculator. This work provides a different strategy for developing an environment-friendly and low-cost water EIPG utilized in harvesting green energy, with no chemical treatment.

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