1 research outputs found
Vapor Phase Processing of α‑Fe<sub>2</sub>O<sub>3</sub> Photoelectrodes for Water Splitting: An Insight into the Structure/Property Interplay
Harvesting radiant energy to trigger
water photoelectrolysis and produce clean hydrogen is receiving increasing
attention in the search of alternative energy resources. In this regard,
hematite (α-Fe<sub>2</sub>O<sub>3</sub>) nanostructures with
controlled nano-organization have been fabricated and investigated
for use as anodes in photoelectrochemical (PEC) cells. The target
systems have been grown on conductive substrates by plasma enhanced-chemical
vapor deposition (PE-CVD) and subjected to eventual ex situ annealing
in air to further tailor their structure and properties. A detailed
multitechnique approach has enabled to elucidate the interrelations
between system characteristics and the generated photocurrent. The
present α-Fe<sub>2</sub>O<sub>3</sub> systems are characterized
by a high purity and hierarchical morphologies consisting of nanopyramids/organized
dendrites, offering a high contact area with the electrolyte. PEC
data reveal a dramatic response enhancement upon thermal treatment,
related to a more efficient electron transfer. The reasons underlying
such a phenomenon are elucidated and discussed by transient absorption
spectroscopy (TAS) studies of photogenerated charge carrier kinetics,
investigated on different time scales for the first time on PE-CVD
Fe<sub>2</sub>O<sub>3</sub> nanostructures