Open this publication in new window or tab >>Show others...
2022 (English)In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 91, article id 106648Article in journal (Refereed) Published
Abstract [en]
A dual-bandgap photoelectrochemical (PEC) cell with two semiconductors stacked in tandem is a widely adopted concept to capture a large fraction of the solar spectrum for water splitting. While two photons are theoretically needed to produce one H2 molecule using single-bandgap PEC cells, four photons are generally required for one H2 molecule in the dual-bandgap cells because of an unavoidable charge recombination at the solid-solid interface. Here, triboelectric effects are exploited in the form of triboelectric nanogenerator (TENG) to allow for the generation of one H2 molecule at the expenses of two photons in a dual-bandgap device using an array of core/shell p-type silicon/anatase-TiO2 nanowires as photoelectrode. The TENG, that converts mechanical energy to electricity, efficiently suppresses the charge recombination at the interface and significantly increases the energy of the photo-generated carriers required for the simultaneous water reduction and oxidation. The synergy of photoexcitation and triboelectrics results in a rate of hydrogen production in a neutral Na2SO4 electrolyte around 150 times higher than that of the counterpart, i.e., the device in the absence of TENG. Furthermore, the TENG-induced enhancement in the PEC water splitting remains substantial even when the solar power density is reduced to 20 mW/cm2.
Place, publisher, year, edition, pages
ElsevierElsevier BV, 2022
Keywords
Photoelectrochemical cells, TENG, Water splitting, Nanowires, Hydrogen
National Category
Physical Chemistry Other Physics Topics
Identifiers
urn:nbn:se:uu:diva-458697 (URN)10.1016/j.nanoen.2021.106648 (DOI)000712506700002 ()
Funder
Swedish Research Council, 2019-05484Swedish Energy Agency, 46641-1Olle Engkvists stiftelse, SOEB-2015/167
Note
De två första författarna delar förstaförfattarskapet
2021-11-292021-11-292024-01-15Bibliographically approved