Multistage amine-modified cellulose nanofibrils as high-performance positive triboelectric materials

The straightforward preparation of amino-modified cellulose-based triboelectric materials with strong electron-donating ability, high contact electrification activity, sustainability, and cost-effectiveness has attracted widespread attention from researchers. Here, three facile and rapid methods have been reported for the multistage synthesis of amino-modified TEMPO-oxidized cellulose nanofibril (TOCN); that is, using small molecules, dendritic, and crosslinked amines to directly modify the carboxylic acid groups unique to TOCN. These modified TOCNs are prepared into dense films and aerogel films for positive triboelectric materials. Comprehensive effects of the amount of amine grafting and specific surface area on triboelectric properties are investigated. The final prepared triboelectric nanogenerator (TENG) device outputs a maximum open-circuit voltage of 217 V, a closed-circuit current of 19.2 μA, and a power density of 1.6 W/m2. This TENG device can be used effectively for human limb sensing and micromechanical energy harvesting.