Chemical Functionalization of Bacterial Cellulose Film for Enhancing Output Performance of Bio-Triboelectric Nanogenerator

Abstract

Triboelectric nanogenerator (TENG) is a promising technology for converting mechanical energy into electrical energy. In the present research, a bio-TENG based on bacterial cellulose (BC) was fabricated, and the performance was improved by surface modification. The BC films were chemically functionalized by phosphorylation and sulfonation processes. The FTIR technique confirmed the functional groups on the phosphorylated and sulfonated BCs. The hydrophobic/hydrophilic properties were studied and found that the unmodified BC, as well as the functionalized BC, were both hydrophilic. The structure and morphology of the BC nanofibers were investigated by SEM imaging. It was shown that after phosphorylation and sulfonation, the BC nanofiber surface became rougher, and the fibers were densely packed. The pores between the nanofibers almost disappeared. These have resulted from the coating of the phosphate and sulfonic functional groups on the BC nanofibers. For TENG measurement, the BC film was paired with PTFE under a single-electrode measuring mode. The functionalized BC showed improved output performance compared to the unmodified BC, possibly due to the rougher and denser BC surface and the change in the BC triboelectric potential. This research demonstrated a novel but straightforward way to enhance the output performance of the bio-TENG.