Mechanical energy harvesting from the motion of water waves is a very promising direction toward the replacement of batteries and fossil fuels with a clean and sustainable energy resource. Triboelectric nanogenerator (TENG) has been introduced recently as a novel and potent technology for this purpose, and the use of TENG for water wave energy harvesting has been investigated to some extent. However, there are two main challenges in this path including:​ A) design of advanced TENG systems for effective wave energy harvesting, and B) development of novel methods and materials for improving the performance of TENG systems. This research addresses the two challenges in three directions including development and analysis of advanced structural designs for TENG-based wave energy harvesters, development of a surface modification technique for the TENG improvement, and development of advanced materials for high performance TENG systems. For the advanced structural design direction, initially a comprehensive analysis is carried out on the performance of a hybridized TENG and electromagnetic (EMG) wave energy harvester based on the duck-shaped structure. Then, a hybridized TENG-EMG wave energy harvester is developed and analyzed based on the heaving point absorber mechanism. Lastly, the heaving hybridized TENG-EMG is fabricated and experimentally evaluated to demonstrate the application of proposed design. For the surface modification direction, a novel and facile method is developed for improving the surface morphology of polymeric layers which are embedded into the TENG. This method is based the hot embossing of polymers on self-assembled micro particles which can effectively boost the output performance of TENG systems. For the advanced materials direction, highly porous polymeric aerogels namely polyimide and polyurethane aerogels are developed and synthesized to be used as the main contact materials in the TENG which can remarkably enhance the TENG electrical output characteristics. In overall, this research provides guidelines toward design and development of high performance TENG-based systems for wave energy harvesting.