Liquid–film triboelectric nanogenerator with the volume effect for low-frequency blue energy harvesting and shock detection

Blue energy is vital for sustainable development, providing a viable alternative to fossil fuels and contributing to climate change mitigation and environmental protection. Triboelectric nanogenerators (TENGs), a novel energy-harvesting technology, have garnered significant attention, particularly for their potential in wave energy harvesting. However, enhancing the performance of solid–liquid TENGs under low-frequency excitation remains challenging. This study addresses this challenge by leveraging the volume effect to substantially enhance the effective output power of liquid–film triboelectric nanogenerators (LF-TENGs). A 5.22-fold increase in output power was achieved, reaching 95.01 μ W, compared to LF-TENGs without the volume effect. When integrated into a cathodic protection system, the LF-TENG reduced the open-circuit potential of aluminium by approximately 320 mV in a 3.5% NaCl solution. The electric energy generated from the triboelectric effect of the LF-TENG can enhance the corrosion protection of metal substrates in marine engineering through cathodic protection. Additionally, a ship shock protection sensor based on LF-TENG further validates its potential in sensing applications. These findings underscore the capability of LF-TENGs to advance marine energy harvesting and corrosion protection technologies, offering a promising solution for sustainable energy generation and infrastructure protection.