Wood-based triboelectric nanogenerator integrated with superhydrophobicity and photothermal-induced self-healing for high-temperature and high-humidity environment

Owing to the unique mechanical and available modification properties, wood is widely used as triboelectric material to construct the triboelectric nanogenerators (TENGs) with mechanical energy-to-electricity conversion ability for applying in passive energy-saving buildings and smart facilities. However, the environmental changes would cause dimension changes and dissipation of surface charge, then decrease the friction efficiency, thus limiting its application prospects in some particular environment, such as the high-temperature and high-humidity environment. Herein, the wood-based tribopositive frictional material (PDMS-CB/Fe3O4@Wood) integrated with superhydrophobicity and photothermal-induced self-healing capability was achieved through in-situ growth of iron oxide (Fe3O4) and dipping polydimethylsiloxanes (PDMS), then triboelectricity and photothermal ability were improved by repeatedly spaying the mixed solution of modified PDMS and carbon black (CB) particles onto the surface. The open-circuit voltage and short-circuit current of the wood-based TENG (3 cm x 3 cm) in contact-separation operation mode is 24.3 V and 0.34 mu A upon 50 N. Particularly, the excellent superhydrophobicity with water contact angle of 156.5 +/- 1 degrees could be restored in similar to 20 min by heat that originated from photo-to-thermal conversion, which overcame the dimensional change of wood and charge dissipation, thus ensure the excellent triboelectric output under high-temperature (100 degrees C) and high-humidity (90 %) conditions. Lastly, the wood-based TENGs could be utilized as energy-harvesting wooden floors capable of powering lamps and other devices, activated by walking or tapping.