Transparent, Flexible Cellulose Nanofibril–Phosphorene Hybrid Paper as Triboelectric Nanogenerator

Few-layered phosphorene is exfoliated through a liquid phase exfoliation in ethanol, acting as an additive to mix with tempo-oxidized cellulose nanofibrils (CNF), forming a transparent, flexible nanogenerator paper. The gas barrier property of CNF protects phosphorene against oxidation in ambient condition. The phosphorene in the hybrid paper is stable over six months even with exposure to ambient condition (23 °C, 70% RH) in air. The hybrid paper is used as an active layer to construct a triboelectric energy nanogenerator (TENG). This hybrid paper shows an open-circuit voltage of 5.2 V with a current density of 1.8 µA cm⁻², which is five and nine times higher than that of the pure CNF paper device, respectively. This work reveals the role of phosphorene in acting as a charge carrier in the hybrid paper and demonstrates a new way to attain stable functional phosphorene hybrids in ambient condition. The resultant phosphorene hybrid paper could be used as a building block for TENG with enhanced output performance.