In Situ Limited Crystallization Enhanced Acoustic Energy Harvesting of CelluMOF Triboelectric Aerogels

Abstract

Cellulosic aerogels, owing to their renewable origin, lightweight porous structure, and excellent structural tunability, have shown broad application prospects in triboelectric energy harvesting. However, cellulosic triboelectric aerogels typically rely on large mechanical deformations to generate electrical signals, making it difficult to achieve efficient energy conversion under weak mechanical disturbances such as acoustic vibrations. Meanwhile, their single surface chemical composition and limited charge trapping capability also restrict triboelectric output performance. In this study, an in situ limited crystallization strategy is proposed, in which coordination interactions are utilized to induce the confined growth of nanocrystals on the fiber network, enabling uniform dispersion of nanostructures within the three-dimensional skeleton while effectively suppressing particle aggregation. Combined with directional freezing technology and surface hydrophobic modification, a cellulosic triboelectric aerogel with both environmental robustness and high output performance is successfully constructed. The aerogel exhibits significantly enhanced triboelectric output performance, achieving a power density of 396 mW m–2 and is capable of harvesting and converting noise energy in industrial environments. This work provides a new material design strategy for regulating the growth behavior of nanocrystals in three-dimensional porous fiber networks and offers guidance for the application of cellulosic triboelectric aerogels in weak vibration energy harvesting and intelligent acoustic sensing.