Photocorrosion-Resistant Sb2Se3 Photocathodes with Earth Abundant MoSx Hydrogen Evolution Catalyst
2017-09-08T17:01:38Z (GMT)
by
<p>The
poor stability of high efficiency photoabsorber materials in aqueous media is
one factor holding back the realization of photoelectrochemical (PEC) water
splitting for large scale, practical solar fuels generation. Here, we
demonstrate that highly efficient thin film Sb<sub>2</sub>Se<sub>3</sub>–fabricated
by a simple, low temperature selenization of electrodeposited Sb–is
intrinsically stable towards photocorrosion in strongly acidic media (1 M H<sub>2</sub>SO<sub>4</sub>).
Coupling with a photoelectrodeposited MoS<sub>x</sub> hydrogen evolution
catalyst gives high photocurrents (5 mA cm<sup>-2</sup> at 0 V vs RHE) and high
stability without protective layers (10 h with ~20% loss). A low temperature sulfurization of the Sb<sub>2</sub>Se<sub>3</sub>-MoS<sub>x</sub>
stack dramatically improved the onset potential, resulting in high photocurrent
densities up to 16 mA cm<sup>-2</sup> at 0 V vs RHE. The simplicity with which
these photocathodes are fabricated, combined with the high photocurrents and
stability, make Sb<sub>2</sub>Se<sub>3</sub> a strong candidate for scalable
PEC cells.</p>