Interfacial charge management in flexible polysiloxane/rGO nanocomposites for high-performance triboelectric nanogenerators

Understanding and controlling interfacial charge management is essential for improving the performance of triboelectric nanogenerators (TENGs). In this work, flexible polysiloxane/reduced graphene oxide (PS/rGO) nanocomposites with different rGO loadings were fabricated to investigate the influence of low-concentration rGO incorporation on the structural, optical, dielectric, and triboelectric properties of the composites. Comprehensive characterization using SEM, XRD, FTIR, Raman spectroscopy, XPS, photoluminescence (PL), dielectric spectroscopy, and triboelectric measurements demonstrated that rGO incorporation modifies the interfacial electronic environment of the polysiloxane matrix by promoting interfacial polarization, facilitating charge transfer, and creating effective charge-trapping sites. Pronounced PL quenching accompanied by a 15 nm (107 meV) blue shift confirmed enhanced electronic interactions between the polymer matrix and rGO nanosheets. The PS/rGO nanocomposite containing 0.05 wt% rGO exhibited the optimum triboelectric performance, generating an open-circuit voltage of 31.5 V, a short-circuit current of 3.0 μA, and a maximum output power of 35 μW (21.9 mW m⁻ 2 ) under ambient conditions (RH = 70–75%). Humidity-dependent measurements further revealed that moisture adsorption significantly accelerates charge dissipation, highlighting the critical role of charge retention in determining the electrical output. The results demonstrate that the triboelectric performance is governed not only by dielectric permittivity but also by the synergistic effects of interfacial polarization, charge trapping, balanced electrical conductivity, and charge retention. These findings provide new mechanistic insights into interfacial charge regulation in graphene-based polymer nanocomposites and offer practical guidelines for the rational design of high-performance flexible triboelectric materials for self-powered energy harvesting applications.