A hole-selective hybrid TiO<sub>2</sub> layer for stable and low-cost photoanodes in solar water oxidation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39487151.
- Also identified by DOI 10.1038/s41467-024-53754-9 and PMC identifier 11530438.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The use of conductive and corrosion-resistant protective layers represents a key strategy for improving the durability of light absorber materials in photoelectrochemical water splitting. For high performance photoanodes such as Si, GaAs, and GaP, amorphous TiO<sub>2</sub> protective overlayers, deposited by atomic layer deposition, are conductive for holes via a defect band in the TiO<sub>2</sub>. However, when coated on simply prepared, low-cost photoanodes such as metal oxides, no charge transfer is observed through amorphous TiO<sub>2</sub>. Here, we report a hybrid polyethyleneimine/TiO<sub>2</sub> layer that facilitates hole transfer from model oxides BiVO<sub>4</sub> and Fe<sub>2</sub>O<sub>3</sub>, enabling access to a broader scope of available materials for practical water oxidation. A thin polyethyleneimine layer between the light absorber and the hybrid polyethyleneimine/TiO<sub>2</sub> acts as a hole-selective interface, improving the optoelectronic properties of the photoanode devices. These polyethyleneimine/TiO<sub>2</sub> modified photoanodes exhibit high photostability for solar water oxidation over 400 h.