1 research outputs found
Amorphous FeOOH Oxygen Evolution Reaction Catalyst for Photoelectrochemical Water Splitting
Reaching the goal of economical photoelectrochemical
(PEC) water
splitting will likely require the combination of efficient solar absorbers
with high activity electrocatalysts for the hydrogen and oxygen evolution
reactions (HER and OER). Toward this goal, we synthesized an amorphous
FeOOH (a-FeOOH) phase that has not previously been studied as an OER
catalyst. The a-FeOOH films show activity comparable to that of another
OER cocatalyst, Co-borate (Co–B<sub>i</sub>), in 1 M Na<sub>2</sub>CO<sub>3</sub>, reaching 10 mA/cm<sup>2</sup> at an overpotential
of ∼550 mV for 10 nm thick films. Additionally, the a-FeOOH
thin films absorb less than 3% of the solar photons (AM1.5G) with
energy greater than 1.9 eV, are homogeneous over large areas, and
act as a protective layer separating the solution from the solar absorber.
The utility of a-FeOOH in a realistic system is tested by depositing
on amorphous Si triple junction solar cells with a photovoltaic efficiency
of 6.8%. The resulting a-FeOOH/a-Si devices achieve a total water
splitting efficiency of 4.3% at 0 V vs RHE in a three-electrode configuration
and show no decrease in efficiency over the course of 4 h