High-performance triboelectric nanogenerator based on NH2-MXene/TiO2@sodium alginate composite film for self-powered cathodic protection

Biodegradable or eco-friendly triboelectric materials from natural polymers are considered promising and viable alternative for the development of green triboelectric nanogenerators (TENGs). Yet, they are mostly struggling from poor mechanical properties and low triboelectric output performance. In this work, we developed a highly efficient NH 2 -MXene/TiO 2 @sodium alginate (NMTS) composite film with NH 2 -MXene/TiO 2 as a filler and sodium alginate (SA) as a matrix and a TENG based on this composite film (NMTS-TENG) was constructed. The tribo-positive characteristic of SA was enhanced by adding NH 2 -MXene and TiO 2 . Different loaded content of the NH 2 -MXene and TiO 2 were explored and optimized to improve mechanical properties of the composite film and the output performance of NMTS-TENG. The microstructure and dielectric constant of the composite films were well characterized to investigate the enhancement mechanism. Under optimal conditions, the tensile strength of the composite film reaches up to 175.0 MPa and surpass the pure SA film. The NMTS-TENG shows the output performance with an open-circuit voltage of 357.6 V and short-circuit current of 55.1 µA, and the output peak power increases by 9.3 times compared with pure SA-based TENG. In addition, we developed a TENG device to harvest ocean wave energy for self-powered cathodic protection. The electrochemical test results reveal that the open circuit potential of the protected Q235 carbon steel can decrease by 74 mV and the corrosion potential decrease by 146.5 mV, indicating the good anti-corrosion properties. This study provides a promising method to develop high-performance biomaterials based TENG and expands the practical application of SA in the field of the electrochemical cathodic protection.