Diethylenetriamine-assisted hydrothermal synthesis of dodecahedral α-Fe₂O₃ nanocrystals with enhanced and stable photoelectrochemical activity

Abstract

Dodecahedral α-Fe 2 O 3 nanocrystals (D-hematite) were successfully synthesized through a hydrothermal method involving FeS-diethylenetriamine (FeS-DETA) hybrid nanosheets as starting materials. The photoanode made by assembling the as-obtained D-hematite on ITO substrates exhibited efficient photoelectrocatalytic water splitting activity and good stability in 1.0 M KOH aqueous solution under visible light irradiation.

Novel Composites of α‐Fe2O3 Tetrakaidecahedron and Graphene Oxide as an Effective Photoelectrode with Enhanced Photocurrent Performances

“…The unique polyhedral nanostructure possesses abundant exposed (110) facets, which have been reported to display better photocatalytic activity than (012), (001) facets and higher PEC activity than commercial α-Fe 2 O 3 nanoparticles. [ 14,31,50 ] And the large number of uncoordinated surface atoms around α-Fe 2 O 3 polyhedron can offer plenty of active sites for the photoinduced reaction. [ 31 ] Good crystallinity of α-Fe 2 O 3 polyhedrons also benefi ts the fast transfer of photogenerated carriers.…”

“…[ 14,31,50 ] And the large number of uncoordinated surface atoms around α-Fe 2 O 3 polyhedron can offer plenty of active sites for the photoinduced reaction. [ 31 ] Good crystallinity of α-Fe 2 O 3 polyhedrons also benefi ts the fast transfer of photogenerated carriers. [ 31 ] In order to improve the PEC activity of pure α-Fe 2 O 3 nanomaterials, graphene oxide was introduced to fabricate a series of α-Fe 2 O 3 /graphene oxide (α-Fe 2 O 3 /GO 1, 2, 3) nanocomposites with different graphene oxide mass ratios of 5%, 10%, and 15%.…”

“…[ 31 ] Good crystallinity of α-Fe 2 O 3 polyhedrons also benefi ts the fast transfer of photogenerated carriers. [ 31 ] In order to improve the PEC activity of pure α-Fe 2 O 3 nanomaterials, graphene oxide was introduced to fabricate a series of α-Fe 2 O 3 /graphene oxide (α-Fe 2 O 3 /GO 1, 2, 3) nanocomposites with different graphene oxide mass ratios of 5%, 10%, and 15%. The PEC performance of α-Fe 2 O 3 /graphene oxide nanocomposites is investigated by photocurrent response tests systematically in Figure 7 .…”

“…The application of α-Fe 2 O 3 polyhedron to photoelectrochemical fi eld has been extended. [ 31 ] They have fabricated the photoanode based on dodecahedral α-Fe 2 O 3 nanocrystals which showed high photoelectrocatalytic activity and fi ne stability under visible light irradiation. The further investigation of α-Fe 2 O 3 polyhedron in PEC process is highly promising and necessary.…”

“…The α-Fe 2 O 3 tetrakaidecahedrons prepared by a hydrothermal process without any organic additives display good crystallinity, which are modifi ed by graphene oxide afterward. Other than the previous reports involving viscous macromolecules, [ 25,27,28 ] F − anion, [ 26 ] and diethylenetriamine, [ 31 ] the hydrothermal synthesis of α-Fe 2 O 3 tetrakaidecahedrons is specially facile and environmental, which only uses FeCl 2 •4H 2 O, NaOH, and ultrapure H 2 O as reaction precursors. Through photoelectrochemical investigation, this kind of α-Fe 2 O 3 /graphene photoelectrode shows superior photocurrent response than that of pure α-Fe 2 O 3 with higher photocurrent and lower onset potential.…”