A graded catalytic-protective layer for an efficient and stable water-splitting photocathode

Document Type

Article

Publication Date

1-13-2017

Abstract

Achieving solar-to-hydrogen efficiencies above 15% is key for the commercial success of photoelectrochemical water-splitting devices. While tandem cells can reach those efficiencies, increasing the catalytic activity and long-term stability remains a significant challenge. Here we show that annealing a bilayer of amorphous titanium dioxide (TiO x) and molybdenum sulfide (MoS x) deposited onto GaInP 2 results in a photocathode with high catalytic activity (current density of 11 mA cm 2 at 0 V versus the reversible hydrogen electrode under 1 sun illumination) and stability (retention of 80% of initial photocurrent density over a 20 h durability test) for the hydrogen evolution reaction. Microscopy and spectroscopy reveal that annealing results in a graded MoS x /MoO x /TiO 2 layer that retains much of the high catalytic activity of amorphous MoS x but with stability similar to crystalline MoS 2. Our findings demonstrate the potential of utilizing a hybridized, heterogeneous surface layer as a cost-effective catalytic and protective interface for solar hydrogen production.

Identifier

85019162565 (Scopus)

Publication Title

Nature Energy

External Full Text Location

https://doi.org/10.1038/nenergy.2016.192

e-ISSN

20587546

Issue

2

Volume

2

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