Solid–liquid triboelectric nanogenerators (S–L TENGs) are extensively researched for their capability to harvest mechanical energy from natural sources. Nevertheless, some TENGs based on friction electrification and electrostatic induction are partially limited, and liquids exhibit slow separation speeds upon contact with solid interfaces, resulting in lower output currents and voltages. This limitation hinders their ability to satisfy real-world electricity demands. This study introduces a wave-driven closed polytetrafluoroethylene tube TENG (PT-TENG) and enhances the conventional tank car model by applying the principle of interface charge transfer. The improvements enable the output current and voltage to reach 900 µA and 150 V, respectively, with a power output of 17.74 mW. This represents a thirteen-fold increase over the traditional model's performance, effectively capturing the kinetic energy of water flow. The mechanism and influencing factors of the PT-TENG are analysed, including the effect of external conditions on the movement state of water flow within the device, to enhance PT-TENG's output. This novel S–L TENG efficiently gathers low-frequency energy, offering a straightforward manufacturing process and elevated output. It enhances charge transfer at the solid–liquid interface and offers a new strategy for harvesting ocean wave energy.