A hybrid energy cell for self-powered water splitting

Production of hydrogen (H2) by splitting water using the electrolysis effect is a potential source of clean and renewable energy. However, it usually requires an external power source to drive the oxidation or reduction reactions of H2O molecules, which largely limits the development of this technology. Here, we fabricated a hybrid energy cell that is an integration of a triboelectric nanogenerator, a thermoelectric cell, and a solar cell, which can be used to simultaneously/individually harvest mechanical, thermal, and/or solar energies. The power output of the hybrid energy cell can be directly used for splitting water without an external power source. The volume of the produced H2 has a linear relationship with the splitting time at a production speed of 4 × 10−4 mL s−1. Moreover, the produced energies can also be stored in a Li-ion battery for water splitting as well as other uses.