Functionalized wood with tunable tribopolarity for efficient triboelectric nanogenerators

Abstract

Summary Wood is a state-of-art, renewable, and sustainable building material with excellent mechanical properties but negligible triboelectric polarizability. Strategies to improve and rationally tune the triboelectric properties of wood are needed to further its application for mechanical\xa0energy harvesting in smart buildings. We found that wood becomes\xa0more triboelectrically positive when modified by in\xa0situ-grown zeolitic imidazolate framework-8 (ZIF-8), a metal-organic framework (MOF), and more triboelectrically negative when coated with poly(dimethylsiloxane) (PDMS). A triboelectric nanogenerator (TENG) made with two radial-cut wood samples (L\xa0× R × T: 35\xa0× 20\xa0× 1\xa0mm3), respectively functionalized with ZIF-8 and PDMS, can generate an open-circuit voltage (Voc) of 24.3\xa0V and a short-circuit current (Isc) of 0.32\xa0μA upon 50 N, 80 times higher compared with that of native wood. We demonstrate the applicability of our functionalized wood TENG (FW-TENG) in smart buildings by using it to power household lamps, calculators, and electrochromic windows.