Autogenic electrolysis of water powered by solar and mechanical energy

A dual-bandgap photoelectrochemical (PEC) cell with two semiconductors stacked in tandem is a widely adopted concept to capture large fraction of the solar spectrum for water splitting. While photons are theoretically needed produce one H2 molecule using single-bandgap PEC cells, four generally required cells because an unavoidable charge recombination at solid-solid interface. Here, triboelectric effects exploited form nanogenerator (TENG) allow generation expenses device array core/shell p-type silicon/anatase-TiO2 nanowires as photoelectrode. The TENG, that converts mechanical energy electricity, efficiently suppresses interface and significantly increases photo-generated carriers simultaneous reduction oxidation. synergy photoexcitation triboelectrics results rate hydrogen production neutral Na2SO4 electrolyte around 150 times higher than counterpart, i.e., absence TENG. Furthermore, TENG-induced enhancement splitting remains substantial even when power density reduced 20 mW/cm2.