Modulation of Electrical Charge Transfer in Cornstarch-Based Films Through Carbonized Polymer Dots and Their Validation as Electrodes in Triboelectric Nanogenerators

Abstract

In this study, electrically conductive cornstarch-based films are developed by incorporating carbonized polymer dots (CPDs), and their charge-transfer capability is evaluated through their electrical characterization and their validation as electrodes in a triboelectric nanogenerator (TENG). The incorporation of controlled amounts of CPDs promoted the formation of conductive pathways within the cornstarch matrix, improved charge transport, and reduced electrical resistance, with a maximum conductivity of 196.602 µΩ−1 cm−1 obtained for the optimized composition. Spectroscopic analyses revealed that this behavior arises from interfacial interactions between the hydroxyl-rich cornstarch chains and functionalized nitrogen-containing CPDs, which facilitate charge transfer within the polymer matrix. An optimal CPD quantity provides a balance between conductive carbon domains and polar surface functionalities, maximizing charge mobility without inducing aggregation. The improved electrical response of the optimized composite film was further validated by implementing it as an electrode in a triboelectric nanogenerator, which exhibited a current of 2.087 µA, corresponding to an approximately 334-fold enhancement compared to a reference device based on pristine cornstarch. These results firstly demonstrate that CPDs provide an effective route for modulating electrical charge transfer in cornstarch-based films and secondly highlight the potential of sustainable polymer composites as low-cost conductive materials for flexible electronics, biodegradable electrodes, and energy-related applications.